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Sat Apr 12 14:36:14 2008 UTC (7 years ago) by ph10
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Do not discard subpatterns with {0} quantifiers, as they may be called as 

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 321 Version 7.7 05-Mar-08
5     ---------------------
7     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
8     a string to a long long, pretend we don't even have a long long." This is
9     done by checking for the strtoq, strtoll, and _strtoi64 functions.
10 ph10 322
11     2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
12     pre-7.6 versions, which defined a global no_arg variable instead of putting
13 ph10 332 it in the RE class. (See also #8 below.)
14 ph10 323
15     3. Remove a line of dead code, identified by coverity and reported by Nuno
16     Lopes.
17 ph10 324
18     4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
19 ph10 321
20 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
21     of files, instead of just to the final components.
23     (2) If there was more than one level of directory, the subdirectories were
24     skipped unless they satisfied the include/exclude conditions. This is
25     inconsistent with GNU grep (and could even be seen as contrary to the
26     pcregrep specification - which I improved to make it absolutely clear).
27     The action now is always to scan all levels of directory, and just
28     apply the include/exclude patterns to regular files.
29 ph10 325
30     5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
31     --exclude_dir in the tests to avoid scanning .svn directories.
32 ph10 326
33     6. Applied Craig's patch to the QuoteMeta function so that it escapes the
34     NUL character as backslash + 0 rather than backslash + NUL, because PCRE
35     doesn't support NULs in patterns.
36 ph10 327
37     7. Added some missing "const"s to declarations of static tables in
38     pcre_compile.c and pcre_dfa_exec.c.
39 ph10 328
40     8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
41 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
42 ph10 330 first patch. And a third patch - this was a messy problem.)
43 ph10 331
44     9. Applied Craig's patch to remove the use of push_back().
45 ph10 321
46 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
47     matching function regexec().
48 ph10 333
49     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
50     which, however, unlike Perl's \g{...}, are subroutine calls, not back
51     references. PCRE supports relative numbers with this syntax (I don't think
52     Oniguruma does).
53 ph10 335
54     12. Previously, a group with a zero repeat such as (...){0} was completely
55     omitted from the compiled regex. However, this means that if the group
56     was called as a subroutine from elsewhere in the pattern, things went wrong
57     (an internal error was given). Such groups are now left in the compiled
58     pattern, with a new opcode that causes them to be skipped at execution
59     time.
60 ph10 324
61 ph10 332
62 ph10 319 Version 7.6 28-Jan-08
63 ph10 300 ---------------------
65 ph10 302 1. A character class containing a very large number of characters with
66     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
67     overflow.
68 ph10 309
69     2. Patch to cut out the "long long" test in pcrecpp_unittest when
70     HAVE_LONG_LONG is not defined.
72 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
73 ph10 304 bring them up to date and include new features. This patch includes:
74 ph10 309
75 ph10 304 - Fixed PH's badly added libz and libbz2 support.
76     - Fixed a problem with static linking.
77 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
78 ph10 304 - Fixed dftables problem and added an option.
79     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
81     - Added readline support for pcretest.
82 ph10 309 - Added an listing of the option settings after cmake has run.
84 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
85     "pcre.dll" under mingw when using Configure/Make. I added stuff to
86     Makefile.am that cause it to include this special target, without
87     affecting anything else. Note that the same mingw target plus all
88     the other distribution libraries and programs are now supported
89     when configuring with CMake (see 6 below) instead of with
90     Configure/Make.
91 ph10 309
92 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
93     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
94 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
95     solves the problem, but it does no harm.
96 ph10 313
97 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
98 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
99 ph10 314 with CMake, and also correct the comment about stack recursion.
100 ph10 313
101 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
102 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
103     of a program that users should build themselves after PCRE is installed, so
104     building it automatically is not really right. What is more, it gave
105 ph10 312 trouble in some build environments.
106 ph10 300
107 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
108 ph10 308
109 ph10 319
110 ph10 298 Version 7.5 10-Jan-08
111 ph10 263 ---------------------
113     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
114     values in parens when parsing an RE using the C++ wrapper."
115 ph10 286
116 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
117     Characters greater than 255 were excluded from the class instead of being
118     included.
119 ph10 286
120     3. The same bug as (2) above applied to negated POSIX classes such as
121 ph10 265 [:^space:].
122 ph10 286
123 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
124     defined or documented. It seems to have been a typo for PCRE_STATIC, so
125 ph10 286 I have changed it.
127 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
128 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
129     first named subpattern whose name started with "a" (in other words, the
130 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
131     expected" is now given for (?&) (a zero-length name), and this patch also
132     makes it give the same error for \k'' (previously it complained that that
133     was a reference to a non-existent subpattern).
134 ph10 286
135 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
136 ph10 286 this is right because (?- can be followed by option settings as well as by
137 ph10 269 digits. I have, however, made the messages clearer.
138 ph10 286
139 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
140     than the number used in the conditional) now cause a compile-time error.
141     This is actually not compatible with Perl, which accepts such patterns, but
142     treats the conditional as always being FALSE (as PCRE used to), but it
143     seems to me that giving a diagnostic is better.
144 ph10 286
145 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
146 ph10 275 and messages.
147 ph10 286
148     9. Fix two occurrences of "backslash" in comments that should have been
149     "backspace".
151     10. Remove two redundant lines of code that can never be obeyed (their function
152     was moved elsewhere).
154     11. The program that makes PCRE's Unicode character property table had a bug
155     which caused it to generate incorrect table entries for sequences of
156 ph10 277 characters that have the same character type, but are in different scripts.
157 ph10 286 It amalgamated them into a single range, with the script of the first of
158 ph10 277 them. In other words, some characters were in the wrong script. There were
159     thirteen such cases, affecting characters in the following ranges:
160 ph10 286
161 ph10 277 U+002b0 - U+002c1
162     U+0060c - U+0060d
163 ph10 286 U+0061e - U+00612
164 ph10 277 U+0064b - U+0065e
165     U+0074d - U+0076d
166     U+01800 - U+01805
167     U+01d00 - U+01d77
168     U+01d9b - U+01dbf
169     U+0200b - U+0200f
170     U+030fc - U+030fe
171     U+03260 - U+0327f
172     U+0fb46 - U+0fbb1
173     U+10450 - U+1049d
174 ph10 286
175 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
176     compatible with GNU grep in that, if there was more than one match in a
177     line, it showed only the first of them. It now behaves in the same way as
178     GNU grep.
179 ph10 286
180     13. If the -o and -v options were combined for pcregrep, it printed a blank
181     line for every non-matching line. GNU grep prints nothing, and pcregrep now
182     does the same. The return code can be used to tell if there were any
183     non-matching lines.
185 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
187     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
188 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
189 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
190     and both kinds of lookbehind were skipped).
192 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
193 ph10 284 inclusion of <windows.h> to before rather than after the definition of
194     INVALID_FILE_ATTRIBUTES (patch from David Byron).
195 ph10 263
196 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
197 ph10 286 character property caused pcre_compile() to compile bad code, which led at
198     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
199     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
200     caused the error; without that there was no problem.
201 ph10 263
202 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
203 ph10 286
204 ph10 289 19. Added --enable-pcretest-libreadline.
205 ph10 286
206 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
207 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
208 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
209     later patch that removed the other one (the right fix) and added unit tests
210     that check the return values (which was not done before).
211 ph10 292
212 ph10 291 21. Several CMake things:
213 ph10 287
214 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
215 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
216 ph10 288
217 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
218     linked with the newly-built libraries, not previously installed ones.
219 ph10 291
221 ph10 298
222     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
223     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
224     UTF-8 newline character). The key issue is that the pattern starts .*;
225     this means that the match must be either at the beginning, or after a
226     newline. The bug was in the code for advancing after a failed match and
227     checking that the new position followed a newline. It was not taking
228 ph10 294 account of UTF-8 characters correctly.
229 ph10 298
230     23. PCRE was behaving differently from Perl in the way it recognized POSIX
231     character classes. PCRE was not treating the sequence [:...:] as a
232     character class unless the ... were all letters. Perl, however, seems to
233     allow any characters between [: and :], though of course it rejects as
234     unknown any "names" that contain non-letters, because all the known class
235     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
236     for example, whereas PCRE did not - it did not recognize a POSIX character
237     class. This seemed a bit dangerous, so the code has been changed to be
238     closer to Perl. The behaviour is not identical to Perl, because PCRE will
239     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
240     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
241     Perl does, and where it didn't before.
243 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
244     Windows environments %n is disabled by default.
245 ph10 292
247 ph10 260 Version 7.4 21-Sep-07
248 ph10 230 ---------------------
250     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
251 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
252     LF". That isn't really right - the whole point of the change was to try to
253     help when there was an actual mention of one of the two characters. So now
254     the change happens only if \r or \n (or a literal CR or LF) character is
255 ph10 230 encountered.
256 ph10 231
257     2. The 32-bit options word was also used for 6 internal flags, but the numbers
258     of both had grown to the point where there were only 3 bits left.
259     Fortunately, there was spare space in the data structure, and so I have
260     moved the internal flags into a new 16-bit field to free up more option
261 ph10 230 bits.
262 ph10 231
263     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
264     but did not set the internal JCHANGED flag - either of these is enough to
265     control the way the "get" function works - but the PCRE_INFO_JCHANGED
266     facility is supposed to tell if (?J) was ever used, so now (?J) at the
267 ph10 230 start sets both bits.
269 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
270     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
271 ph10 230
272 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
274     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
275 ph10 233 compatibility, even though it is no longer used.
276 ph10 243
277     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
278 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
279 ph10 259 windows.h file is present (where different names are used). [This was
280 ph10 257 reversed later after testing - see 16 below.]
281 ph10 243
282     8. Changed all #include <config.h> to #include "config.h". There were also
283 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
284 ph10 243
285 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
286 ph10 243 sequence off the lines that it output.
288     10. It was pointed out to me that arrays of string pointers cause lots of
289     relocations when a shared library is dynamically loaded. A technique of
290     using a single long string with a table of offsets can drastically reduce
291     these. I have refactored PCRE in four places to do this. The result is
292 ph10 240 dramatic:
293 ph10 243
294 ph10 240 Originally: 290
295     After changing UCP table: 187
296 ph10 243 After changing error message table: 43
297 ph10 240 After changing table of "verbs" 36
298     After changing table of Posix names 22
299 ph10 243
300 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
301 ph10 247
302 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
303 ph10 247 unicode-properties was also set.
305 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
306 ph10 231
307 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
308     checked only for CRLF.
309 ph10 233
310 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
312 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
313 ph10 253
314 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
315 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
316     entirely. This removes changes made in 7 above.
317 ph10 256
318 ph10 261 17. The CMake files have been updated, and there is now more information about
319     building with CMake in the NON-UNIX-USE document.
320 ph10 257
321 ph10 261
322 ph10 228 Version 7.3 28-Aug-07
323 ph10 157 ---------------------
325 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
326     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
327     brackets there is not right, since it causes compilers to look for an
328     installed pcre.h, not the version that is in the source that is being
329     compiled (which of course may be different). I have changed it back to:
330 ph10 197
331 ph10 189 #include "pcre.h"
332 ph10 197
333     I have a vague recollection that the change was concerned with compiling in
334     different directories, but in the new build system, that is taken care of
335     by the VPATH setting the Makefile.
337 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
338     when the subject happened to end in the byte 0x85 (e.g. if the last
339     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
340     characters but of course it shouldn't be taken as a newline when it is part
341     of another character. The bug was that, for an unlimited repeat of . in
342     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
343     characters when looking for a newline.
344 ph10 197
345     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
347     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
348     in debug output.
350 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
351     long printing in the pcrecpp unittest when running under MinGW.
352 ph10 189
353 ph10 197 6. ESC_K was left out of the EBCDIC table.
354 ph10 189
355 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
356     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
357     limit also applies to "virtual nesting" when a pattern is recursive, and in
358     this case 1000 isn't so big. I have been able to remove this limit at the
359     expense of backing off one optimization in certain circumstances. Normally,
360     when pcre_exec() would call its internal match() function recursively and
361     immediately return the result unconditionally, it uses a "tail recursion"
362     feature to save stack. However, when a subpattern that can match an empty
363     string has an unlimited repetition quantifier, it no longer makes this
364     optimization. That gives it a stack frame in which to save the data for
365     checking that an empty string has been matched. Previously this was taken
366     from the 1000-entry workspace that had been reserved. So now there is no
367     explicit limit, but more stack is used.
368 ph10 189
369 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
370     syntax that is required for Windows, and which was going wrong for the
371     pcreposix and pcrecpp parts of the library. These were overlooked when this
372     problem was solved for the main library.
373 ph10 197
374 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
375     the size of patterns that contain repeated groups with explicit upper
376     limits. As the maximum quantifier is 65535, the maximum group length was
377     set at 30,000 so that the product of these two numbers did not overflow a
378     32-bit integer. However, it turns out that people want to use groups that
379     are longer than 30,000 bytes (though not repeat them that many times).
380     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
381     made it possible to implement the integer overflow checks in a much more
382     dynamic way, which I have now done. The artificial limitation on group
383     length has been removed - we now have only the limit on the total length of
384     the compiled pattern, which depends on the LINK_SIZE setting.
385 ph10 208
386     10. Fixed a bug in the documentation for get/copy named substring when
387     duplicate names are permitted. If none of the named substrings are set, the
388     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
389     empty string.
391     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
392     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
393     because the ] is interpreted as the first data character and the
394     terminating ] is not found. PCRE has been made compatible with Perl in this
395     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
396     cause memory overwriting.
398 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
399     string has been matched (to stop an infinite loop). It was not recognizing
400 ph10 208 a conditional subpattern that could match an empty string if that
401 ph10 206 subpattern was within another subpattern. For example, it looped when
402 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
403 ph10 206 condition was not nested. This bug has been fixed.
404 ph10 208
405 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
406     past the start of the subject in the presence of bytes with the top bit
407     set, for example "\x8aBCD".
408 ph10 211
409 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
410     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
411 ph10 200
412 ph10 211 14. Optimized (?!) to (*FAIL).
413 ph10 202
414 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
415     This restricts code points to be within the range 0 to 0x10FFFF, excluding
416     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
417     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
418     does: it's just the validity check that is more restrictive.
419 ph10 220
420     16. Inserted checks for integer overflows during escape sequence (backslash)
421     processing, and also fixed erroneous offset values for syntax errors during
422     backslash processing.
424 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
425 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
427 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
428     caused an overrun.
429 ph10 220
430     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
431     something other than just ASCII characters) inside a group that had an
432     unlimited repeat caused a loop at compile time (while checking to see
433     whether the group could match an empty string).
435 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
436     [\P{Any}] did so. (Error in the code for printing property names.)
437 ph10 210
438 ph10 220 21. An orphan \E inside a character class could cause a crash.
440     22. A repeated capturing bracket such as (A)? could cause a wild memory
441 ph10 218 reference during compilation.
442 ph10 220
443     23. There are several functions in pcre_compile() that scan along a compiled
444     expression for various reasons (e.g. to see if it's fixed length for look
445 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
446 ph10 220 present in the pattern. These operators have additional parameters compared
447     with \d, etc, and these were not being taken into account when moving along
448 ph10 218 the compiled data. Specifically:
449 ph10 220
450     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
451     length.
453     (b) An item such as \pL+ within a repeated group could cause crashes or
454 ph10 218 loops.
455 ph10 220
456 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
457 ph10 220 "reference to non-existent subpattern" error.
459 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
461 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
462 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
463 ph10 211
464 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
465 ph10 218
466 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
467 ph10 223 character were causing crashes (broken optimization).
468 ph10 227
469 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
470 ph10 227 \p or \P) caused a compile-time loop.
472 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
473     break. For example, the unstudied pattern [\r\n]A does not match the string
474     "\r\nA" because change 7.0/46 below moves the current point on by two
475     characters after failing to match at the start. However, the pattern \nA
476 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
477     the same is true. There doesn't seem any very clean way out of this, but
478     what I have chosen to do makes the common cases work: PCRE now takes note
479     of whether there can be an explicit match for \r or \n anywhere in the
480     pattern, and if so, 7.0/46 no longer applies. As part of this change,
481     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
482     pattern has explicit CR or LF references.
483 ph10 222
484 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
485 ph10 223
486 ph10 227
487 ph10 189 Version 7.2 19-Jun-07
488     ---------------------
490 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
491     which is apparently normally available under Windows.
492 ph10 159
493     2. Re-jig the pcregrep tests with different newline settings in an attempt
494     to make them independent of the local environment's newline setting.
495 ph10 157
496 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
497 ph10 165
498 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
499     was not 2, because the output contained actual offsets. The recent new
500 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
501     usable with all link sizes.
503 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
504     stack recursion. This gives a massive performance boost under BSD, but just
505 ph10 165 a small improvement under Linux. However, it saves one field in the frame
506 ph10 164 in all cases.
507 ph10 172
508 ph10 166 6. Added more features from the forthcoming Perl 5.10:
509 ph10 172
510 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
511     recursion call. It refers to the nth most recently opened parentheses.
512 ph10 172
513 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
514 ph10 172 to be opened parentheses.
516     (c) Conditions that refer to capturing parentheses can be specified
517 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
518 ph10 172
519 ph10 168 (d) \K resets the start of the current match so that everything before
520 ph10 172 is not part of it.
522 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
523 ph10 172
524 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
525 ph10 172 reference syntax.
526 ph10 182
527 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
528 ph10 182 alternative starts with the same number.
529 ph10 172
530 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
532 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
535     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
536     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
537 ph10 170 for detecting groups that can match an empty string.
538 ph10 159
539 ph10 172 9. A pattern with a very large number of alternatives (more than several
540     hundred) was running out of internal workspace during the pre-compile
541     phase, where pcre_compile() figures out how much memory will be needed. A
542     bit of new cunning has reduced the workspace needed for groups with
543     alternatives. The 1000-alternative test pattern now uses 12 bytes of
544     workspace instead of running out of the 4096 that are available.
545 ph10 182
546 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
547 ph10 172
548 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
549     The report of the bug said:
550 ph10 182
551 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
552     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
553 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
554 ph10 185
555 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
556 ph10 185 it matched the wrong number of bytes.
557 ph10 172
558 ph10 179
559 ph10 155 Version 7.1 24-Apr-07
560 ph10 98 ---------------------
562 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
563 ph10 122 that is more "standard", making use of automake and other Autotools. There
564 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
565     on this.
566 ph10 111
567     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
568     for recursive directory scanning broke on some systems because the files
569     are not scanned in any specific order and on different systems the order
570     was different. A call to "sort" has been inserted into RunGrepTest for the
571     approprate test as a short-term fix. In the longer term there may be an
572 ph10 100 alternative.
573 ph10 111
574 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
575 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
576     people do their own conversions for various reasons). The problems
577     concerned the use of low-level troff macros .br and .in. I have therefore
578     removed all such uses from the man pages (some were redundant, some could
579 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
580     HTML has been updated to handle .nf/.fi and to complain if it encounters
581     .br or .in.
582 ph10 111
583 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
584 ph10 123 arranged for config.h to be included in the distribution, with the name
585 ph10 111 config.h.generic, for the benefit of those who have to compile without
586     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
588     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
589     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
590 ph10 127 makevp.bat for the current PCRE, using the additional files
591 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
592 ph10 111
593     6. A Windows user reported a minor discrepancy with test 2, which turned out
594     to be caused by a trailing space on an input line that had got lost in his
595 ph10 102 copy. The trailing space was an accident, so I've just removed it.
596 ph10 111
597 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
598 ph10 111 that is needed.
600 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
601     as "const" (a) because they are and (b) because it helps the PHP
602     maintainers who have recently made a script to detect big data structures
603 ph10 111 in the php code that should be moved to the .rodata section. I remembered
604     to update Builducptable as well, so it won't revert if ucptable.h is ever
605 ph10 105 re-created.
606 ph10 111
607     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
608 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
609 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
610     support is not required. This saves 1.5-2K of code, which is important in
611 ph10 107 some applications.
612 ph10 111
613 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
614 ph10 111 so as not to refer to the tables, even though these functions will never be
615     called when UTF-8 support is disabled. Otherwise there are problems with a
616     shared library.
618 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
620     (a) It was defining its arguments as char * instead of void *.
622 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
623     a long time ago when I wrote it, but is no longer the case.
625 ph10 118 The emulated memove() is provided for those environments that have neither
626 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
627 ph10 118 is clearly not the case, as these two bugs were recently reported.
628 ph10 123
629 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
630 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
631     pages, and it removes trailing spaces from listed files. It also creates
632     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
633     case, it wraps all the #defines with #ifndefs. This script should be run
634 ph10 111 before "make dist".
635 ph10 123
636 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
637     with Unicode property support.
638 ph10 123
639     (a) For a maximizing quantifier, if the two different cases of the
640     character were of different lengths in their UTF-8 codings (there are
641     some cases like this - I found 11), and the matching function had to
642 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
643     were both the same length.
644 ph10 123
645     (b) When PCRE was configured to use the heap rather than the stack for
646     recursion during matching, it was not correctly preserving the data for
647     the other case of a UTF-8 character when checking ahead for a match
648     while processing a minimizing repeat. If the check also involved
649 ph10 115 matching a wide character, but failed, corruption could cause an
650     erroneous result when trying to check for a repeat of the original
651     character.
652 ph10 123
653 ph10 116 13. Some tidying changes to the testing mechanism:
654 ph10 98
655 ph10 116 (a) The RunTest script now detects the internal link size and whether there
656     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
657 ph10 123 values substituted by "configure". (The RunGrepTest script already did
658     this for UTF-8.) The configure.ac script no longer substitutes the
659     relevant variables.
661 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
662     with length and offset values. This means that the output is different
663     for different internal link sizes. Test 2 is skipped for link sizes
664     other than 2 because of this, bypassing the problem. Unfortunately,
665     there was also a test in test 3 (the locale tests) that used /B and
666 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
667     I have added a new /Z option to pcretest that replaces the length and
668     offset values with spaces. This is now used to make test 3 independent
669 ph10 122 of link size. (Test 2 will be tidied up later.)
670 ph10 123
671     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
672 ph10 122 segmentation fault instead of returning the appropriate error message.
673 ph10 134
674 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
675 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
676     This doesn't seem right; it now treats the CRLF combination as the line
677     ending, and so does not match in that case. It's only a pattern such as ^$
678     that would hit this one: something like ^ABC$ would have failed after \r
679     and then tried again after \r\n.
681 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
682 ph10 134 in an attempt to make files that differ only in their line terminators
683     compare equal. This works on Linux.
684 ph10 142
685 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
686     as it exited. This is now fixed, thanks to valgrind.
687 ph10 142
688 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
689 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
690     was because its rules for how to advance for /g after matching an empty
691 ph10 143 string at the end of a line did not allow for this case. They now check for
692     it specially.
693 ph10 150
694     20. pcretest is supposed to handle patterns and data of any length, by
695     extending its buffers when necessary. It was getting this wrong when the
696 ph10 147 buffer for a data line had to be extended.
697 ph10 150
698 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
699 ph10 150 CRLF as a newline sequence.
700 ph10 152
701 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
702 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
703     I have nevertheless tidied it up.
704 ph10 111
705 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
706 ph10 123
707 ph10 153 24. Added a man page for pcre-config.
708 ph10 152
709 ph10 153
710 nigel 93 Version 7.0 19-Dec-06
711     ---------------------
713     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
714     moving to gcc 4.1.1.
716     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
717     sys/time.h, which is documented as needed for this function. It doesn't
718     seem to matter on Linux, but it showed up on some releases of OS X.
720     3. It seems that there are systems where bytes whose values are greater than
721     127 match isprint() in the "C" locale. The "C" locale should be the
722     default when a C program starts up. In most systems, only ASCII printing
723     characters match isprint(). This difference caused the output from pcretest
724     to vary, making some of the tests fail. I have changed pcretest so that:
726     (a) When it is outputting text in the compiled version of a pattern, bytes
727     other than 32-126 are always shown as hex escapes.
729     (b) When it is outputting text that is a matched part of a subject string,
730     it does the same, unless a different locale has been set for the match
731     (using the /L modifier). In this case, it uses isprint() to decide.
733     4. Fixed a major bug that caused incorrect computation of the amount of memory
734     required for a compiled pattern when options that changed within the
735     pattern affected the logic of the preliminary scan that determines the
736     length. The relevant options are -x, and -i in UTF-8 mode. The result was
737     that the computed length was too small. The symptoms of this bug were
738     either the PCRE error "internal error: code overflow" from pcre_compile(),
739     or a glibc crash with a message such as "pcretest: free(): invalid next
740     size (fast)". Examples of patterns that provoked this bug (shown in
741     pcretest format) are:
743     /(?-x: )/x
744     /(?x)(?-x: \s*#\s*)/
745     /((?i)[\x{c0}])/8
746     /(?i:[\x{c0}])/8
748     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
749     is now done differently.
751     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
752     wrapper classes; (b) implement a new function in the C++ scanner that is
753     more efficient than the old way of doing things because it avoids levels of
754     recursion in the regex matching; (c) add a paragraph to the documentation
755     for the FullMatch() function.
757     6. The escape sequence \n was being treated as whatever was defined as
758     "newline". Not only was this contrary to the documentation, which states
759     that \n is character 10 (hex 0A), but it also went horribly wrong when
760     "newline" was defined as CRLF. This has been fixed.
762     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
763     was being set to -1 for the "end of line" case (supposedly a value that no
764     character can have). Though this value is never used (the check for end of
765     line is "zero bytes in current character"), it caused compiler complaints.
766     I've changed it to 0xffffffff.
768     8. In pcre_version.c, the version string was being built by a sequence of
769     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
770     string (as it is for production releases) called a macro with an empty
771     argument. The C standard says the result of this is undefined. The gcc
772     compiler treats it as an empty string (which was what was wanted) but it is
773     reported that Visual C gives an error. The source has been hacked around to
774     avoid this problem.
776     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
777     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
778     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
779     of them did).
781     10. Originally, pcretest opened its input and output without "b"; then I was
782     told that "b" was needed in some environments, so it was added for release
783     5.0 to both the input and output. (It makes no difference on Unix-like
784     systems.) Later I was told that it is wrong for the input on Windows. I've
785     now abstracted the modes into two macros, to make it easier to fiddle with
786     them, and removed "b" from the input mode under Windows.
788     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
790     12. Added -help and --help to pcretest as an official way of being reminded
791     of the options.
793     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
794     and pcrecpp.cc because they annoy compilers at high warning levels.
796     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
798     15. Fixed an occurrence of == in configure.ac that should have been = (shell
799     scripts are not C programs :-) and which was not noticed because it works
800     on Linux.
802     16. pcretest is supposed to handle any length of pattern and data line (as one
803     line or as a continued sequence of lines) by extending its input buffer if
804     necessary. This feature was broken for very long pattern lines, leading to
805     a string of junk being passed to pcre_compile() if the pattern was longer
806     than about 50K.
808     17. I have done a major re-factoring of the way pcre_compile() computes the
809     amount of memory needed for a compiled pattern. Previously, there was code
810     that made a preliminary scan of the pattern in order to do this. That was
811     OK when PCRE was new, but as the facilities have expanded, it has become
812     harder and harder to keep it in step with the real compile phase, and there
813     have been a number of bugs (see for example, 4 above). I have now found a
814     cunning way of running the real compile function in a "fake" mode that
815     enables it to compute how much memory it would need, while actually only
816     ever using a few hundred bytes of working memory and without too many
817     tests of the mode. This should make future maintenance and development
818     easier. A side effect of this work is that the limit of 200 on the nesting
819     depth of parentheses has been removed (though this was never a serious
820     limitation, I suspect). However, there is a downside: pcre_compile() now
821     runs more slowly than before (30% or more, depending on the pattern). I
822     hope this isn't a big issue. There is no effect on runtime performance.
824     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
825     newline (only possible for the last line of a file) and it was a
826     pattern that set a locale (followed by /Lsomething), pcretest crashed.
828     19. Added additional timing features to pcretest. (1) The -tm option now times
829     matching only, not compiling. (2) Both -t and -tm can be followed, as a
830     separate command line item, by a number that specifies the number of
831     repeats to use when timing. The default is 50000; this gives better
832     precision, but takes uncomfortably long for very large patterns.
834     20. Extended pcre_study() to be more clever in cases where a branch of a
835     subpattern has no definite first character. For example, (a*|b*)[cd] would
836     previously give no result from pcre_study(). Now it recognizes that the
837     first character must be a, b, c, or d.
839     21. There was an incorrect error "recursive call could loop indefinitely" if
840     a subpattern (or the entire pattern) that was being tested for matching an
841     empty string contained only one non-empty item after a nested subpattern.
842     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
843     incorrectly, because the \d was being skipped in the check.
845     22. The pcretest program now has a new pattern option /B and a command line
846     option -b, which is equivalent to adding /B to every pattern. This causes
847     it to show the compiled bytecode, without the additional information that
848     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
849     is the same as /B/I).
851     23. A new optimization is now able automatically to treat some sequences such
852     as a*b as a*+b. More specifically, if something simple (such as a character
853     or a simple class like \d) has an unlimited quantifier, and is followed by
854     something that cannot possibly match the quantified thing, the quantifier
855     is automatically "possessified".
857     24. A recursive reference to a subpattern whose number was greater than 39
858     went wrong under certain circumstances in UTF-8 mode. This bug could also
859     have affected the operation of pcre_study().
861     25. Realized that a little bit of performance could be had by replacing
862     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
864     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
866     27. Possessive quantifiers such as a++ were previously implemented by turning
867     them into atomic groups such as ($>a+). Now they have their own opcodes,
868     which improves performance. This includes the automatically created ones
869     from 23 above.
871     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
872     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
873     the first matched character to be a colon. This applied both to named and
874     numbered groups.
876     29. The ucpinternal.h header file was missing its idempotency #ifdef.
878     30. I was sent a "project" file called libpcre.a.dev which I understand makes
879     building PCRE on Windows easier, so I have included it in the distribution.
881     31. There is now a check in pcretest against a ridiculously large number being
882     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
883     loop, the loop is abandoned.
885     32. Forward references to subpatterns in conditions such as (?(2)...) where
886     subpattern 2 is defined later cause pcre_compile() to search forwards in
887     the pattern for the relevant set of parentheses. This search went wrong
888     when there were unescaped parentheses in a character class, parentheses
889     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
891     33. "Subroutine" calls and backreferences were previously restricted to
892     referencing subpatterns earlier in the regex. This restriction has now
893     been removed.
895     34. Added a number of extra features that are going to be in Perl 5.10. On the
896     whole, these are just syntactic alternatives for features that PCRE had
897     previously implemented using the Python syntax or my own invention. The
898     other formats are all retained for compatibility.
900     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
901     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
902     also .NET compatible.
904     (b) A recursion or subroutine call to a named group can now be defined as
905     (?&name) as well as (?P>name).
907     (c) A backreference to a named group can now be defined as \k<name> or
908     \k'name' as well as (?P=name). The new forms, as well as being in Perl
909     5.10, are also .NET compatible.
911     (d) A conditional reference to a named group can now use the syntax
912     (?(<name>) or (?('name') as well as (?(name).
914     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
915     groups (named and numbered) that are never evaluated inline, but can be
916     called as "subroutines" from elsewhere. In effect, the DEFINE condition
917     is always false. There may be only one alternative in such a group.
919     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
920     as the simple (?(R). The condition is true only if the most recent
921     recursion is that of the given number or name. It does not search out
922     through the entire recursion stack.
924     (g) The escape \gN or \g{N} has been added, where N is a positive or
925     negative number, specifying an absolute or relative reference.
927     35. Tidied to get rid of some further signed/unsigned compiler warnings and
928     some "unreachable code" warnings.
930     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
931     things, this adds five new scripts.
933     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
934     There were also incompatibilities regarding the handling of \Q..\E inside
935     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
936     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
938     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
939     matches an empty string, and forcibly breaks the loop. There were bugs in
940     this code in non-simple cases. For a pattern such as ^(a()*)* matched
941     against aaaa the result was just "a" rather than "aaaa", for example. Two
942     separate and independent bugs (that affected different cases) have been
943     fixed.
945     39. Refactored the code to abolish the use of different opcodes for small
946     capturing bracket numbers. This is a tidy that I avoided doing when I
947     removed the limit on the number of capturing brackets for 3.5 back in 2001.
948     The new approach is not only tidier, it makes it possible to reduce the
949     memory needed to fix the previous bug (38).
951     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
952     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
953     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
954     mode.
956     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
957     report.
959     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
960     copy construction and assignment in the C++ wrapper.
962     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
963     couple of bugs that could have given wrong results in the "--newline=crlf"
964     case.
966     44. Added a number of casts and did some reorganization of signed/unsigned int
967     variables following suggestions from Dair Grant. Also renamed the variable
968     "this" as "item" because it is a C++ keyword.
970     45. Arranged for dftables to add
972     #include "pcre_internal.h"
974     to pcre_chartables.c because without it, gcc 4.x may remove the array
975     definition from the final binary if PCRE is built into a static library and
976     dead code stripping is activated.
978     46. For an unanchored pattern, if a match attempt fails at the start of a
979     newline sequence, and the newline setting is CRLF or ANY, and the next two
980     characters are CRLF, advance by two characters instead of one.
983 nigel 91 Version 6.7 04-Jul-06
984     ---------------------
986     1. In order to handle tests when input lines are enormously long, pcretest has
987     been re-factored so that it automatically extends its buffers when
988     necessary. The code is crude, but this _is_ just a test program. The
989     default size has been increased from 32K to 50K.
991     2. The code in pcre_study() was using the value of the re argument before
992     testing it for NULL. (Of course, in any sensible call of the function, it
993     won't be NULL.)
995     3. The memmove() emulation function in pcre_internal.h, which is used on
996     systems that lack both memmove() and bcopy() - that is, hardly ever -
997     was missing a "static" storage class specifier.
999     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1000     containing an extended class (one that cannot be represented by a bitmap
1001     because it contains high-valued characters or Unicode property items, e.g.
1002     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1003     pattern, but PCRE should not loop if you do not (it no longer does).
1004     [Detail: two cases were found: (a) a repeated subpattern containing an
1005     extended class; (b) a recursive reference to a subpattern that followed a
1006     previous extended class. It wasn't skipping over the extended class
1007     correctly when UTF-8 mode was not set.]
1009     5. A negated single-character class was not being recognized as fixed-length
1010     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1011     compile error "lookbehind assertion is not fixed length".
1013     6. The RunPerlTest auxiliary script was showing an unexpected difference
1014     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1015     write a Perl script that can interpret lines of an input file either as
1016     byte characters or as UTF-8, which is what "perltest" was being required to
1017     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1018     can't do is switch easily at run time between having the "use utf8;" pragma
1019     or not. In the end, I fudged it by using the RunPerlTest script to insert
1020     "use utf8;" explicitly for the UTF-8 tests.
1022     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1023     the end of the subject string, contrary to the documentation and to what
1024     Perl does. This was true of both matching functions. Now it matches only at
1025     the start of the subject and immediately after *internal* newlines.
1027     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1028     a pointer to an int instead of a pointer to an unsigned long int. This
1029     caused problems on 64-bit systems.
1031     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1032     instance of the 'standard' template library not being so standard".
1034     10. There was no check on the number of named subpatterns nor the maximum
1035     length of a subpattern name. The product of these values is used to compute
1036     the size of the memory block for a compiled pattern. By supplying a very
1037     long subpattern name and a large number of named subpatterns, the size
1038     computation could be caused to overflow. This is now prevented by limiting
1039     the length of names to 32 characters, and the number of named subpatterns
1040     to 10,000.
1042     11. Subpatterns that are repeated with specific counts have to be replicated in
1043     the compiled pattern. The size of memory for this was computed from the
1044     length of the subpattern and the repeat count. The latter is limited to
1045     65535, but there was no limit on the former, meaning that integer overflow
1046     could in principle occur. The compiled length of a repeated subpattern is
1047     now limited to 30,000 bytes in order to prevent this.
1049     12. Added the optional facility to have named substrings with the same name.
1051     13. Added the ability to use a named substring as a condition, using the
1052     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1053     are numbers (not recommended). Forward references are permitted.
1055     14. Added forward references in named backreferences (if you see what I mean).
1057     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1058     pattern could run off the end of the subject. For example, the pattern
1059     "(?s)(.{1,5})"8 did this with the subject "ab".
1061     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1062     PCRE_CASELESS was set when matching characters that were quantified with ?
1063     or *.
1065     17. A character class other than a single negated character that had a minimum
1066     but no maximum quantifier - for example [ab]{6,} - was not handled
1067     correctly by pce_dfa_exec(). It would match only one character.
1069     18. A valid (though odd) pattern that looked like a POSIX character
1070     class but used an invalid character after [ (for example [[,abc,]]) caused
1071     pcre_compile() to give the error "Failed: internal error: code overflow" or
1072     in some cases to crash with a glibc free() error. This could even happen if
1073     the pattern terminated after [[ but there just happened to be a sequence of
1074     letters, a binary zero, and a closing ] in the memory that followed.
1076     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1077     over the years. Originally (before any Unicode support), just the bottom 8
1078     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1079     output from "man perlunicode" includes this:
1081     The regular expression compiler produces polymorphic opcodes. That
1082     is, the pattern adapts to the data and automatically switches to
1083     the Unicode character scheme when presented with Unicode data--or
1084     instead uses a traditional byte scheme when presented with byte
1085     data.
1087     Sadly, a wide octal escape does not cause a switch, and in a string with
1088     no other multibyte characters, these octal escapes are treated as before.
1089     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1090     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1091     Unicode string.
1093     I have not perpetrated such confusion in PCRE. Up till now, it took just
1094     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1095     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1096     translate to the appropriate multibyte character.
1098     29. Applied some refactoring to reduce the number of warnings from Microsoft
1099     and Borland compilers. This has included removing the fudge introduced
1100     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1101     a warning about an unused variable.
1103     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1104     characters since release 4.0, because Perl (from release 5.004) does not.
1105     [Or at least, is documented not to: some releases seem to be in conflict
1106     with the documentation.] However, when a pattern was studied with
1107     pcre_study() and all its branches started with \s, PCRE still included VT
1108     as a possible starting character. Of course, this did no harm; it just
1109     caused an unnecessary match attempt.
1111     22. Removed a now-redundant internal flag bit that recorded the fact that case
1112     dependency changed within the pattern. This was once needed for "required
1113     byte" processing, but is no longer used. This recovers a now-scarce options
1114     bit. Also moved the least significant internal flag bit to the most-
1115     significant bit of the word, which was not previously used (hangover from
1116     the days when it was an int rather than a uint) to free up another bit for
1117     the future.
1119     23. Added support for CRLF line endings as well as CR and LF. As well as the
1120     default being selectable at build time, it can now be changed at runtime
1121     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1122     specify that it is scanning data with non-default line endings.
1124     24. Changed the definition of CXXLINK to make it agree with the definition of
1125     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1127     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1128     recursions. This makes a big different to stack usage for some patterns.
1130     26. If a subpattern containing a named recursion or subroutine reference such
1131     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1132     the space required for the compiled pattern went wrong and gave too small a
1133     value. Depending on the environment, this could lead to "Failed: internal
1134     error: code overflow at offset 49" or "glibc detected double free or
1135     corruption" errors.
1137     27. Applied patches from Google (a) to support the new newline modes and (b) to
1138     advance over multibyte UTF-8 characters in GlobalReplace.
1140     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1141     difference for some implementation of PCRE in some Windows version.
1143     29. Added some extra testing facilities to pcretest:
1145     \q<number> in a data line sets the "match limit" value
1146     \Q<number> in a data line sets the "match recursion limt" value
1147     -S <number> sets the stack size, where <number> is in megabytes
1149     The -S option isn't available for Windows.
1152 nigel 89 Version 6.6 06-Feb-06
1153     ---------------------
1155     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1156     in pcreposix.h. I have copied the definition from pcre.h.
1158     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1159     because pcre.h is no longer a built file.
1161     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1162     not normally included in the compiled code.
1165 nigel 87 Version 6.5 01-Feb-06
1166     ---------------------
1168     1. When using the partial match feature with pcre_dfa_exec(), it was not
1169     anchoring the second and subsequent partial matches at the new starting
1170     point. This could lead to incorrect results. For example, with the pattern
1171     /1234/, partially matching against "123" and then "a4" gave a match.
1173     2. Changes to pcregrep:
1175     (a) All non-match returns from pcre_exec() were being treated as failures
1176     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1177     error message is output. Some extra information is given for the
1179     probably the only errors that are likely to be caused by users (by
1180     specifying a regex that has nested indefinite repeats, for instance).
1181     If there are more than 20 of these errors, pcregrep is abandoned.
1183     (b) A binary zero was treated as data while matching, but terminated the
1184     output line if it was written out. This has been fixed: binary zeroes
1185     are now no different to any other data bytes.
1187     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1188     used to set a locale for matching. The --locale=xxxx long option has
1189     been added (no short equivalent) to specify a locale explicitly on the
1190     pcregrep command, overriding the environment variables.
1192     (d) When -B was used with -n, some line numbers in the output were one less
1193     than they should have been.
1195     (e) Added the -o (--only-matching) option.
1197     (f) If -A or -C was used with -c (count only), some lines of context were
1198     accidentally printed for the final match.
1200     (g) Added the -H (--with-filename) option.
1202     (h) The combination of options -rh failed to suppress file names for files
1203     that were found from directory arguments.
1205     (i) Added the -D (--devices) and -d (--directories) options.
1207     (j) Added the -F (--fixed-strings) option.
1209     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1211     (l) Added the --colo(u)r option.
1213     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1214     is not present by default.
1216     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1217     items such as (?R) or (?1), when the recursion could match a number of
1218     alternatives. If it matched one of the alternatives, but subsequently,
1219     outside the recursion, there was a failure, the code tried to back up into
1220     the recursion. However, because of the way PCRE is implemented, this is not
1221     possible, and the result was an incorrect result from the match.
1223     In order to prevent this happening, the specification of recursion has
1224     been changed so that all such subpatterns are automatically treated as
1225     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1227     4. I had overlooked the fact that, in some locales, there are characters for
1228     which isalpha() is true but neither isupper() nor islower() are true. In
1229     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1230     and ordfeminine) are like this. This affected the treatment of \w and \W
1231     when they appeared in character classes, but not when they appeared outside
1232     a character class. The bit map for "word" characters is now created
1233     separately from the results of isalnum() instead of just taking it from the
1234     upper, lower, and digit maps. (Plus the underscore character, of course.)
1236     5. The above bug also affected the handling of POSIX character classes such as
1237     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1238     permanent tables. Instead, the bit maps for such a class were previously
1239     created as the appropriate unions of the upper, lower, and digit bitmaps.
1240     Now they are created by subtraction from the [[:word:]] class, which has
1241     its own bitmap.
1243     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1244     It is created by subtracting the vertical space characters (\x09, \x0a,
1245     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1246     subtraction was done in the overall bitmap for a character class, meaning
1247     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1248     be recognized. This bug has been fixed.
1250     7. Patches from the folks at Google:
1252     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1253     real life, but is still worth protecting against".
1255     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1256     regular expressions".
1258     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1259     have it.
1261     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1262     "configure" and the latter not, in order to fix a problem somebody had
1263     with compiling the Arg class on HP-UX.
1265     (e) Improve the error-handling of the C++ wrapper a little bit.
1267     (f) New tests for checking recursion limiting.
1269     8. The pcre_memmove() function, which is used only if the environment does not
1270     have a standard memmove() function (and is therefore rarely compiled),
1271     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1272     returning a result (though PCRE never actually uses the result).
1274     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1275     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1276     returned instead of calling malloc() with an overflowing number that would
1277     most likely cause subsequent chaos.
1279     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1281     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1282     with this option is matched, the nmatch and pmatch options of regexec() are
1283     ignored.
1285     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1286     provided in case anyone wants to the the POSIX interface with UTF-8
1287     strings.
1289     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1290     C++ linking (needed for some HP-UX environments).
1292     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1293     (unused parameter) and in the pcre_printint() function (omitted "default"
1294     switch label when the default is to do nothing).
1296     15. Added some code to make it possible, when PCRE is compiled as a C++
1297     library, to replace subject pointers for pcre_exec() with a smart pointer
1298     class, thus making it possible to process discontinuous strings.
1300     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1301     much the same function. They were added by different people who were trying
1302     to make PCRE easy to compile on non-Unix systems. It has been suggested
1303     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1304     for compiling on Windows systems. I have therefore replaced it with
1305     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1306     defaults to "extern" for C or "extern C" for C++, which works fine on
1307     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1308     SCOPE with something explicit in config.h. In addition:
1310     (a) pcreposix.h still had just "extern" instead of either of these macros;
1311     I have replaced it with PCRE_DATA_SCOPE.
1313     (b) Functions such as _pcre_xclass(), which are internal to the library,
1314     but external in the C sense, all had PCRE_EXPORT in their definitions.
1315     This is apparently wrong for the Windows case, so I have removed it.
1316     (It makes no difference on Unix-like systems.)
1318     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1319     of recursive calls to match(). This is different to MATCH_LIMIT because
1320     that limits the total number of calls to match(), not all of which increase
1321     the depth of recursion. Limiting the recursion depth limits the amount of
1322     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1323     when PCRE is compiled, and changed at run time. A patch from Google adds
1324     this functionality to the C++ interface.
1326     18. Changes to the handling of Unicode character properties:
1328     (a) Updated the table to Unicode 4.1.0.
1330     (b) Recognize characters that are not in the table as "Cn" (undefined).
1332     (c) I revised the way the table is implemented to a much improved format
1333     which includes recognition of ranges. It now supports the ranges that
1334     are defined in UnicodeData.txt, and it also amalgamates other
1335     characters into ranges. This has reduced the number of entries in the
1336     table from around 16,000 to around 3,000, thus reducing its size
1337     considerably. I realized I did not need to use a tree structure after
1338     all - a binary chop search is just as efficient. Having reduced the
1339     number of entries, I extended their size from 6 bytes to 8 bytes to
1340     allow for more data.
1342     (d) Added support for Unicode script names via properties such as \p{Han}.
1344     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1345     matching that character.
1347     20. When matching a repeated Unicode property with a minimum greater than zero,
1348     (for example \pL{2,}), PCRE could look past the end of the subject if it
1349     reached it while seeking the minimum number of characters. This could
1350     happen only if some of the characters were more than one byte long, because
1351     there is a check for at least the minimum number of bytes.
1353     21. Refactored the implementation of \p and \P so as to be more general, to
1354     allow for more different types of property in future. This has changed the
1355     compiled form incompatibly. Anybody with saved compiled patterns that use
1356     \p or \P will have to recompile them.
1358     22. Added "Any" and "L&" to the supported property types.
1360     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1361     but give a compile time error if the value is greater than 0xff.
1363     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1364     accidentally not being installed or uninstalled.
1366     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1367     made were to insert the current release number. This seemed silly, because
1368     it made things harder for people building PCRE on systems that don't run
1369     "configure". I have turned pcre.h into a distributed file, no longer built
1370     by "configure", with the version identification directly included. There is
1371     no longer a pcre.h.in file.
1373     However, this change necessitated a change to the pcre-config script as
1374     well. It is built from pcre-config.in, and one of the substitutions was the
1375     release number. I have updated configure.ac so that ./configure now finds
1376     the release number by grepping pcre.h.
1378     26. Added the ability to run the tests under valgrind.
1381 nigel 85 Version 6.4 05-Sep-05
1382     ---------------------
1384     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1385     "--" to be printed when multiple files were scanned, even when none of the
1386     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1387     consider it to be a bug, and have restored the previous behaviour.
1389     2. A couple of code tidies to get rid of compiler warnings.
1391     3. The pcretest program used to cheat by referring to symbols in the library
1392     whose names begin with _pcre_. These are internal symbols that are not
1393     really supposed to be visible externally, and in some environments it is
1394     possible to suppress them. The cheating is now confined to including
1395     certain files from the library's source, which is a bit cleaner.
1397     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1398     file's purpose clearer.
1400     5. Reorganized pcre_ucp_findchar().
1403 nigel 83 Version 6.3 15-Aug-05
1404     ---------------------
1406     1. The file libpcre.pc.in did not have general read permission in the tarball.
1408     2. There were some problems when building without C++ support:
1410     (a) If C++ support was not built, "make install" and "make test" still
1411     tried to test it.
1413     (b) There were problems when the value of CXX was explicitly set. Some
1414     changes have been made to try to fix these, and ...
1416     (c) --disable-cpp can now be used to explicitly disable C++ support.
1418     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1419     backslash in a target when C++ was disabled. This confuses some
1420     versions of "make", apparently. Using an intermediate variable solves
1421     this. (Same for CPP_LOBJ.)
1423     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1424     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1425     necessary on certain architectures.
1427     4. Added a setting of -export-symbols-regex to the link command to remove
1428     those symbols that are exported in the C sense, but actually are local
1429     within the library, and not documented. Their names all begin with
1430     "_pcre_". This is not a perfect job, because (a) we have to except some
1431     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1432     available (and never for static libraries). I have made a note to try to
1433     find a way round (a) in the future.
1436 nigel 81 Version 6.2 01-Aug-05
1437     ---------------------
1439     1. There was no test for integer overflow of quantifier values. A construction
1440     such as {1111111111111111} would give undefined results. What is worse, if
1441     a minimum quantifier for a parenthesized subpattern overflowed and became
1442     negative, the calculation of the memory size went wrong. This could have
1443     led to memory overwriting.
1445     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1447     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1448     operating environments where this matters.
1450     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1451     PCRE options from within the C++ wrapper.
1453     5. Named capturing subpatterns were not being correctly counted when a pattern
1454     was compiled. This caused two problems: (a) If there were more than 100
1455     such subpatterns, the calculation of the memory needed for the whole
1456     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1457     back references of the form \12, where the number was greater than 9, were
1458     not recognized as back references, even though there were sufficient
1459     previous subpatterns.
1461     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1462     versions of gcc, e.g. 2.95.4.
1465 nigel 79 Version 6.1 21-Jun-05
1466     ---------------------
1468     1. There was one reference to the variable "posix" in pcretest.c that was not
1469     surrounded by "#if !defined NOPOSIX".
1471     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1472     the cross-check on the old pcre_info() function, for the benefit of the
1473     cut-down version of PCRE that is currently imported into Exim.
1475     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1476     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1477     patterns that start (?i) but I don't think that matters. The use of (?i) is
1478     just an example; this all applies to the other options as well.
1480     4. Since libtool seems to echo the compile commands it is issuing, the output
1481     from "make" can be reduced a bit by putting "@" in front of each libtool
1482     compile command.
1484     5. Patch from the folks at Google for configure.in to be a bit more thorough
1485     in checking for a suitable C++ installation before trying to compile the
1486     C++ stuff. This should fix a reported problem when a compiler was present,
1487     but no suitable headers.
1489     6. The man pages all had just "PCRE" as their title. I have changed them to
1490     be the relevant file name. I have also arranged that these names are
1491     retained in the file doc/pcre.txt, which is a concatenation in text format
1492     of all the man pages except the little individual ones for each function.
1494     7. The NON-UNIX-USE file had not been updated for the different set of source
1495     files that come with release 6. I also added a few comments about the C++
1496     wrapper.
1499 nigel 77 Version 6.0 07-Jun-05
1500     ---------------------
1502     1. Some minor internal re-organization to help with my DFA experiments.
1504     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1505     didn't matter for the library itself when fully configured, but did matter
1506     when compiling without UCP support, or within Exim, where the ucp files are
1507     not imported.
1509     3. Refactoring of the library code to split up the various functions into
1510     different source modules. The addition of the new DFA matching code (see
1511     below) to a single monolithic source would have made it really too
1512     unwieldy, quite apart from causing all the code to be include in a
1513     statically linked application, when only some functions are used. This is
1514     relevant even without the DFA addition now that patterns can be compiled in
1515     one application and matched in another.
1517     The downside of splitting up is that there have to be some external
1518     functions and data tables that are used internally in different modules of
1519     the library but which are not part of the API. These have all had their
1520     names changed to start with "_pcre_" so that they are unlikely to clash
1521     with other external names.
1523     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1524     a different (DFA) algorithm. Although it is slower than the original
1525     function, it does have some advantages for certain types of matching
1526     problem.
1528     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1529     including restarting after a partial match.
1531     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1532     defined when compiling for Windows was sent to me. I have put it into the
1533     code, though I have no means of testing or verifying it.
1535     7. Added the pcre_refcount() auxiliary function.
1537     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1538     match before or at the first newline in the subject string. In pcretest,
1539     the /f option on a pattern can be used to set this.
1541     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1542     would behave wrongly. This has been present in PCRE since release 4.0.
1544     10. A number of changes to the pcregrep command:
1546     (a) Refactored how -x works; insert ^(...)$ instead of setting
1547     PCRE_ANCHORED and checking the length, in preparation for adding
1548     something similar for -w.
1550     (b) Added the -w (match as a word) option.
1552     (c) Refactored the way lines are read and buffered so as to have more
1553     than one at a time available.
1555     (d) Implemented a pcregrep test script.
1557     (e) Added the -M (multiline match) option. This allows patterns to match
1558     over several lines of the subject. The buffering ensures that at least
1559     8K, or the rest of the document (whichever is the shorter) is available
1560     for matching (and similarly the previous 8K for lookbehind assertions).
1562     (f) Changed the --help output so that it now says
1564     -w, --word-regex(p)
1566     instead of two lines, one with "regex" and the other with "regexp"
1567     because that confused at least one person since the short forms are the
1568     same. (This required a bit of code, as the output is generated
1569     automatically from a table. It wasn't just a text change.)
1571     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1572     option but starts with a hyphen. Could be a pattern or a path name
1573     starting with a hyphen, for instance.
1575     (h) "-" can be given as a file name to represent stdin.
1577     (i) When file names are being printed, "(standard input)" is used for
1578     the standard input, for compatibility with GNU grep. Previously
1579     "<stdin>" was used.
1581     (j) The option --label=xxx can be used to supply a name to be used for
1582     stdin when file names are being printed. There is no short form.
1584     (k) Re-factored the options decoding logic because we are going to add
1585     two more options that take data. Such options can now be given in four
1586     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1588     (l) Added the -A, -B, and -C options for requesting that lines of context
1589     around matches be printed.
1591     (m) Added the -L option to print the names of files that do not contain
1592     any matching lines, that is, the complement of -l.
1594     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1595     continue to scan other files.
1597     (o) The -s option was incorrectly implemented. For compatibility with other
1598     greps, it now suppresses the error message for a non-existent or non-
1599     accessible file (but not the return code). There is a new option called
1600     -q that suppresses the output of matching lines, which was what -s was
1601     previously doing.
1603     (p) Added --include and --exclude options to specify files for inclusion
1604     and exclusion when recursing.
1606     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1607     Hopefully, it now does.
1609     12. Missing cast in pcre_study().
1611     13. Added an "uninstall" target to the makefile.
1613     14. Replaced "extern" in the function prototypes in Makefile.in with
1614     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1615     world, but is set differently for Windows.
1617     15. Added a second compiling function called pcre_compile2(). The only
1618     difference is that it has an extra argument, which is a pointer to an
1619     integer error code. When there is a compile-time failure, this is set
1620     non-zero, in addition to the error test pointer being set to point to an
1621     error message. The new argument may be NULL if no error number is required
1622     (but then you may as well call pcre_compile(), which is now just a
1623     wrapper). This facility is provided because some applications need a
1624     numeric error indication, but it has also enabled me to tidy up the way
1625     compile-time errors are handled in the POSIX wrapper.
1627     16. Added VPATH=.libs to the makefile; this should help when building with one
1628     prefix path and installing with another. (Or so I'm told by someone who
1629     knows more about this stuff than I do.)
1631     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1632     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1633     match everything, including newlines. This is not POSIX-compatible, but
1634     somebody wanted the feature. From pcretest it can be activated by using
1635     both the P and the s flags.
1637     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1639     19. libpcre.pc was being incorrectly installed as executable.
1641     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1642     it now also looks for '\r' so that it will work unmodified on Windows.
1644     21. Added Google's contributed C++ wrapper to the distribution.
1646     22. Added some untidy missing memory free() calls in pcretest, to keep
1647     Electric Fence happy when testing.
1651 nigel 75 Version 5.0 13-Sep-04
1652     ---------------------
1654     1. Internal change: literal characters are no longer packed up into items
1655     containing multiple characters in a single byte-string. Each character
1656     is now matched using a separate opcode. However, there may be more than one
1657     byte in the character in UTF-8 mode.
1659     2. The pcre_callout_block structure has two new fields: pattern_position and
1660     next_item_length. These contain the offset in the pattern to the next match
1661     item, and its length, respectively.
1663     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1664     insertion of callouts before each pattern item. Added the /C option to
1665     pcretest to make use of this.
1667     4. On the advice of a Windows user, the lines
1669     #if defined(_WIN32) || defined(WIN32)
1670     _setmode( _fileno( stdout ), 0x8000 );
1671     #endif /* defined(_WIN32) || defined(WIN32) */
1673     have been added to the source of pcretest. This apparently does useful
1674     magic in relation to line terminators.
1676     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1677     for the benefit of those environments where the "b" makes a difference.
1679     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1680     to know about it. I have put a hack into configure.in that adds in code
1681     to set GCC=yes if CC=icc. This seems to end up at a point in the
1682     generated configure script that is early enough to affect the setting of
1683     compiler options, which is what is needed, but I have no means of testing
1684     whether it really works. (The user who reported this had patched the
1685     generated configure script, which of course I cannot do.)
1687     LATER: After change 22 below (new libtool files), the configure script
1688     seems to know about icc (and also ecc). Therefore, I have commented out
1689     this hack in configure.in.
1691     7. Added support for pkg-config (2 patches were sent in).
1693     8. Negated POSIX character classes that used a combination of internal tables
1694     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1695     [[:^ascii]]. Typically, they would match almost any characters. The other
1696     POSIX classes were not broken in this way.
1698     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1699     to find the match, as PCRE was deluded into thinking that the match had to
1700     start at the start point or following a newline. The same bug applied to
1701     patterns with negative forward assertions or any backward assertions
1702     preceding ".*" at the start, unless the pattern required a fixed first
1703     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1705     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1706     starting at the last subject character, bytes beyond the end of the subject
1707     string were read.
1709     11. Renamed the variable "class" as "classbits" to make life easier for C++
1710     users. (Previously there was a macro definition, but it apparently wasn't
1711     enough.)
1713     12. Added the new field "tables" to the extra data so that tables can be passed
1714     in at exec time, or the internal tables can be re-selected. This allows
1715     a compiled regex to be saved and re-used at a later time by a different
1716     program that might have everything at different addresses.
1718     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1719     -R library as well as a -L library.
1721     14. The debugging options of pcretest (-d on the command line or D on a
1722     pattern) showed incorrect output for anything following an extended class
1723     that contained multibyte characters and which was followed by a quantifier.
1725     15. Added optional support for general category Unicode character properties
1726     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1727     support. It adds about 90K to the size of the library. The meanings of the
1728     inbuilt class escapes such as \d and \s have NOT been changed.
1730     16. Updated pcredemo.c to include calls to free() to release the memory for the
1731     compiled pattern.
1733     17. The generated file chartables.c was being created in the source directory
1734     instead of in the building directory. This caused the build to fail if the
1735     source directory was different from the building directory, and was
1736     read-only.
1738     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1739     file. No doubt somebody will tell me if they don't make sense... Also added
1740     Dan Mooney's comments about building on OpenVMS.
1742     19. Added support for partial matching via the PCRE_PARTIAL option for
1743     pcre_exec() and the \P data escape in pcretest.
1745     20. Extended pcretest with 3 new pattern features:
1747     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1748     write the compiled pattern to the file whose name is "rest-of-line".
1749     This is a straight binary dump of the data, with the saved pointer to
1750     the character tables forced to be NULL. The study data, if any, is
1751     written too. After writing, pcretest reads a new pattern.
1753     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1754     compiled pattern from the given file. There must not be any
1755     occurrences of "<" in the file name (pretty unlikely); if there are,
1756     pcretest will instead treat the initial "<" as a pattern delimiter.
1757     After reading in the pattern, pcretest goes on to read data lines as
1758     usual.
1760     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1761     and 16-bit fields in a compiled pattern, to simulate a pattern that
1762     was compiled on a host of opposite endianness.
1764     21. The pcre-exec() function can now cope with patterns that were compiled on
1765     hosts of opposite endianness, with this restriction:
1767     As for any compiled expression that is saved and used later, the tables
1768     pointer field cannot be preserved; the extra_data field in the arguments
1769     to pcre_exec() should be used to pass in a tables address if a value
1770     other than the default internal tables were used at compile time.
1772     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1773     now diagnosed as an error. Previously, most of the time, a negative number
1774     would have been treated as zero, but if in addition "ovector" was passed as
1775     NULL, a crash could occur.
1777     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1778     new versions from the libtool 1.5 distribution (the last one is a copy of
1779     a file called libtool.m4). This seems to have fixed the need to patch
1780     "configure" to support Darwin 1.3 (which I used to do). However, I still
1781     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1782     workstation).
1784     24. Changed the PCRE licence to be the more standard "BSD" licence.
1787 nigel 73 Version 4.5 01-Dec-03
1788     ---------------------
1790     1. There has been some re-arrangement of the code for the match() function so
1791     that it can be compiled in a version that does not call itself recursively.
1792     Instead, it keeps those local variables that need separate instances for
1793     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1794     needs to "recurse". Keeping track of where control must go is done by means
1795     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1796     hide most of the details from the main code, and operates only if
1797     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1798     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1799     operating.
1801     To make it easier for callers to provide specially tailored get/free
1802     functions for this usage, two new functions, pcre_stack_malloc, and
1803     pcre_stack_free, are used. They are always called in strict stacking order,
1804     and the size of block requested is always the same.
1806     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1807     PCRE has been compiled to use the stack or the heap for recursion. The
1808     -C option of pcretest uses this to show which version is compiled.
1810     A new data escape \S, is added to pcretest; it causes the amounts of store
1811     obtained and freed by both kinds of malloc/free at match time to be added
1812     to the output.
1814     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1815     what's available on my current Linux desktop machine.
1817     3. When matching a UTF-8 string, the test for a valid string at the start has
1818     been extended. If start_offset is not zero, PCRE now checks that it points
1819     to a byte that is the start of a UTF-8 character. If not, it returns
1820     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1821     this is necessary because there may be backward assertions in the pattern.
1822     When matching the same subject several times, it may save resources to use
1823     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1825     4. The code for checking the validity of UTF-8 strings has been tightened so
1826     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1827     containing "overlong sequences".
1829     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1830     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1831     should have been "&", but it just so happened that all the cases this let
1832     through by mistake were picked up later in the function.
1834     6. I had used a variable called "isblank" - this is a C99 function, causing
1835     some compilers to warn. To avoid this, I renamed it (as "blankclass").
1837     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1838     prompting; (b) run "./pcretest /dev/null" at the start of the test script
1839     so the version is shown; (c) stop "make test" echoing "./RunTest".
1841     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1843     9. The prototype for memmove() for systems that don't have it was using
1844     size_t, but the inclusion of the header that defines size_t was later. I've
1845     moved the #includes for the C headers earlier to avoid this.
1847     10. Added some adjustments to the code to make it easier to compiler on certain
1848     special systems:
1850     (a) Some "const" qualifiers were missing.
1851     (b) Added the macro EXPORT before all exported functions; by default this
1852     is defined to be empty.
1853     (c) Changed the dftables auxiliary program (that builds chartables.c) so
1854     that it reads its output file name as an argument instead of writing
1855     to the standard output and assuming this can be redirected.
1857     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1858     class containing characters with values greater than 255, PCRE compilation
1859     went into a loop.
1861     12. A recursive reference to a subpattern that was within another subpattern
1862     that had a minimum quantifier of zero caused PCRE to crash. For example,
1863     (x(y(?2))z)? provoked this bug with a subject that got as far as the
1864     recursion. If the recursively-called subpattern itself had a zero repeat,
1865     that was OK.
1867     13. In pcretest, the buffer for reading a data line was set at 30K, but the
1868     buffer into which it was copied (for escape processing) was still set at
1869     1024, so long lines caused crashes.
1871     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1872     "internal error: code overflow...". This applied to any character class
1873     that was followed by a possessive quantifier.
1875     15. Modified the Makefile to add libpcre.la as a prerequisite for
1876     libpcreposix.la because I was told this is needed for a parallel build to
1877     work.
1879     16. If a pattern that contained .* following optional items at the start was
1880     studied, the wrong optimizing data was generated, leading to matching
1881     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1882     matching string must start with a or b or c. The correct conclusion for
1883     this pattern is that a match can start with any character.
1886 nigel 71 Version 4.4 13-Aug-03
1887     ---------------------
1889     1. In UTF-8 mode, a character class containing characters with values between
1890     127 and 255 was not handled correctly if the compiled pattern was studied.
1891     In fixing this, I have also improved the studying algorithm for such
1892     classes (slightly).
1894     2. Three internal functions had redundant arguments passed to them. Removal
1895     might give a very teeny performance improvement.
1897     3. Documentation bug: the value of the capture_top field in a callout is *one
1898     more than* the number of the hightest numbered captured substring.
1900     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1901     in incorrectly linking with a previously installed version. They now link
1902     explicitly with libpcre.la.
1904     5. configure.in no longer needs to recognize Cygwin specially.
1906     6. A problem in pcre.in for Windows platforms is fixed.
1908     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1909     pcretest, it used to include the size of the study block as part of its
1910     output. Unfortunately, the structure contains a field that has a different
1911     size on different hardware architectures. This meant that the tests that
1912     showed this size failed. As the block is currently always of a fixed size,
1913     this information isn't actually particularly useful in pcretest output, so
1914     I have just removed it.
1916     8. Three pre-processor statements accidentally did not start in column 1.
1917     Sadly, there are *still* compilers around that complain, even though
1918     standard C has not required this for well over a decade. Sigh.
1920     9. In pcretest, the code for checking callouts passed small integers in the
1921     callout_data field, which is a void * field. However, some picky compilers
1922     complained about the casts involved for this on 64-bit systems. Now
1923     pcretest passes the address of the small integer instead, which should get
1924     rid of the warnings.
1926     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1927     both compile and run time, and gives an error if an invalid UTF-8 sequence
1928     is found. There is a option for disabling this check in cases where the
1929     string is known to be correct and/or the maximum performance is wanted.
1931     11. In response to a bug report, I changed one line in Makefile.in from
1933     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1934     to
1935     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1937     to look similar to other lines, but I have no way of telling whether this
1938     is the right thing to do, as I do not use Windows. No doubt I'll get told
1939     if it's wrong...
1942 nigel 69 Version 4.3 21-May-03
1943     ---------------------
1945     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1946     Makefile.
1948     2. Some refactoring to improve the quality of the code:
1950     (i) The utf8_table... variables are now declared "const".
1952     (ii) The code for \cx, which used the "case flipping" table to upper case
1953     lower case letters, now just substracts 32. This is ASCII-specific,
1954     but the whole concept of \cx is ASCII-specific, so it seems
1955     reasonable.
1957     (iii) PCRE was using its character types table to recognize decimal and
1958     hexadecimal digits in the pattern. This is silly, because it handles
1959     only 0-9, a-f, and A-F, but the character types table is locale-
1960     specific, which means strange things might happen. A private
1961     table is now used for this - though it costs 256 bytes, a table is
1962     much faster than multiple explicit tests. Of course, the standard
1963     character types table is still used for matching digits in subject
1964     strings against \d.
1966     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1967     ending in _t are). So I've renamed it as ESC_tee.
1969     3. The first argument for regexec() in the POSIX wrapper should have been
1970     defined as "const".
1972     4. Changed pcretest to use malloc() for its buffers so that they can be
1973     Electric Fenced for debugging.
1975     5. There were several places in the code where, in UTF-8 mode, PCRE would try
1976     to read one or more bytes before the start of the subject string. Often this
1977     had no effect on PCRE's behaviour, but in some circumstances it could
1978     provoke a segmentation fault.
1980     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1981     to try to read one or more bytes before the start of the subject string.
1983     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1984     UTF-8 support could misbehave in various ways if the subject string
1985     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1986     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1987     back over UTF-8 characters.)
1990 nigel 67 Version 4.2 14-Apr-03
1991     ---------------------
1993     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1995     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1996     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1997     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1998     [WIN_PREFIX]: new variable, "cyg" for Cygwin
1999     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2000     and BUILD_EXEEXT
2001     Note: automatic setting of the BUILD variables is not yet working
2002     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2003     compile-time but not at link-time
2004     [LINK]: use for linking executables only
2005     make different versions for Windows and non-Windows
2006     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2007     libraries
2008     [LINK_FOR_BUILD]: new variable
2009     [OBJEXT]: use throughout
2010     [EXEEXT]: use throughout
2011     <winshared>: new target
2012     <wininstall>: new target
2013     <dftables.o>: use native compiler
2014     <dftables>: use native linker
2015     <install>: handle Windows platform correctly
2016     <clean>: ditto
2017     <check>: ditto
2018     copy DLL to top builddir before testing
2020     As part of these changes, -no-undefined was removed again. This was reported
2021     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2022     in any case.
2024     3. Some tidies to get rid of compiler warnings:
2026     . In the match_data structure, match_limit was an unsigned long int, whereas
2027     match_call_count was an int. I've made them both unsigned long ints.
2029     . In pcretest the fact that a const uschar * doesn't automatically cast to
2030     a void * provoked a warning.
2032     . Turning on some more compiler warnings threw up some "shadow" variables
2033     and a few more missing casts.
2035     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2036     option, a class that contained a single character with a value between 128
2037     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2039     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2040     option, a class that contained several characters, but with at least one
2041     whose value was between 128 and 255 caused PCRE to crash.
2044 nigel 65 Version 4.1 12-Mar-03
2045     ---------------------
2046 nigel 63
2047 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2048     needed, and a string in dftables.c that was longer than standard compilers are
2049     required to support.
2051     2. Compiling with Sun's compiler found a few more places where the code could
2052     be tidied up in order to avoid warnings.
2054     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2055     first of these names is deprecated in the latest Autoconf in favour of the name
2056     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2057     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2058     analogy I have changed it to CFLAGS_FOR_BUILD.
2060     4. Added -no-undefined to the linking command in the Makefile, because this is
2061     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2062     linking step for the pcreposix library.
2064     5. PCRE was failing to diagnose the case of two named groups with the same
2065     name.
2067     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2068     literal character that is needed in the subject for a match, and scans along to
2069     ensure that it is present before embarking on the full matching process. This
2070     saves time in cases of nested unlimited repeats that are never going to match.
2071     Problem: the scan can take a lot of time if the subject is very long (e.g.
2072     megabytes), thus penalizing straightforward matches. It is now done only if the
2073     amount of subject to be scanned is less than 1000 bytes.
2075     7. A lesser problem with the same optimization is that it was recording the
2076     first character of an anchored pattern as "needed", thus provoking a search
2077     right along the subject, even when the first match of the pattern was going to
2078     fail. The "needed" character is now not set for anchored patterns, unless it
2079     follows something in the pattern that is of non-fixed length. Thus, it still
2080     fulfils its original purpose of finding quick non-matches in cases of nested
2081     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2084     Version 4.0 17-Feb-03
2085     ---------------------
2087 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2088     extended to the end of string, PCRE compiled incorrect data. This could lead to
2089     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2091     2. Moved to autoconf 2.53 and libtool 1.4.2.
2093     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2094     the special perltest8 script is no longer needed - all the tests can be run
2095     from a single perltest script.
2097     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2098     by \s. It has now been removed in PCRE. This means it isn't recognized as
2099     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2100     class [:space:] *does* include VT, thereby creating a mess.
2102     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2103     space and tab.
2105     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2106     its new features into the main test script, reducing the number of scripts.
2108     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2109     were backward compatible, and made the (?i) apply to the whole pattern, as if
2110     /i were given. Now it behaves more logically, and applies the option setting
2111     only to what follows. PCRE has been changed to follow suit. However, if it
2112     finds options settings right at the start of the pattern, it extracts them into
2113     the global options, as before. Thus, they show up in the info data.
2115     8. Added support for the \Q...\E escape sequence. Characters in between are
2116     treated as literals. This is slightly different from Perl in that $ and @ are
2117     also handled as literals inside the quotes. In Perl, they will cause variable
2118     interpolation. Note the following examples:
2120     Pattern PCRE matches Perl matches
2122     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2123     \Qabc\$xyz\E abc\$xyz abc\$xyz
2124     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2126     For compatibility with Perl, \Q...\E sequences are recognized inside character
2127     classes as well as outside them.
2129     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2130     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2131     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2132     signed/unsigned warnings.
2134     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2135     option for pcretest, so I've replaced it by a simple function that does just
2136     that job.
2138     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2139     "pcregrep -".
2141     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2142     Java package. This provides some syntactic sugar for simple cases of what my
2143     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2144     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2145     item, you can use this simplified notation. Note that only makes sense with
2146     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2147     greediness, whatever the setting of the PCRE_UNGREEDY option.
2149     13. A change of greediness default within a pattern was not taking effect at
2150     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2151     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2152     was abstracted outside.
2154     14. PCRE now supports the \G assertion. It is true when the current matching
2155     position is at the start point of the match. This differs from \A when the
2156     starting offset is non-zero. Used with the /g option of pcretest (or similar
2157     code), it works in the same way as it does for Perl's /g option. If all
2158     alternatives of a regex begin with \G, the expression is anchored to the start
2159     match position, and the "anchored" flag is set in the compiled expression.
2161     15. Some bugs concerning the handling of certain option changes within patterns
2162     have been fixed. These applied to options other than (?ims). For example,
2163     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2164     been the other way round. Some of this was related to change 7 above.
2166     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2167     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2168     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2169     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2171     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2172     mode. Unlike ".", it always matches newline, whatever the setting of
2173     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2174     assertions. Perl allows it, but it doesn't (in general) work because it can't
2175     calculate the length of the lookbehind. At least, that's the case for Perl
2176     5.8.0 - I've been told they are going to document that it doesn't work in
2177     future.
2179     18. Added an error diagnosis for escapes that PCRE does not support: these are
2180     \L, \l, \N, \P, \p, \U, \u, and \X.
2182     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2183     reading past the end of the pattern in cases such as /[abcd/.
2185     20. PCRE was getting more memory than necessary for patterns with classes that
2186     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2188     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2189     compiling PCRE for use with Virtual Pascal.
2191     22. Small fix to the Makefile to make it work properly if the build is done
2192     outside the source tree.
2194     23. Added a new extension: a condition to go with recursion. If a conditional
2195     subpattern starts with (?(R) the "true" branch is used if recursion has
2196     happened, whereas the "false" branch is used only at the top level.
2198     24. When there was a very long string of literal characters (over 255 bytes
2199     without UTF support, over 250 bytes with UTF support), the computation of how
2200     much memory was required could be incorrect, leading to segfaults or other
2201     strange effects.
2203     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2204     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2205     there was a subsequent back reference to those brackets. This meant that, for
2206     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2207     possible to check for precisely this case. All we can do is abandon the
2208     optimization if .* occurs inside capturing brackets when there are any back
2209     references whatsoever. (See below for a better fix that came later.)
2211     26. The handling of the optimization for finding the first character of a
2212     non-anchored pattern, and for finding a character that is required later in the
2213     match were failing in some cases. This didn't break the matching; it just
2214     failed to optimize when it could. The way this is done has been re-implemented.
2216     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2218     28. Added a new feature that provides some of the functionality that Perl
2219     provides with (?{...}). The facility is termed a "callout". The way it is done
2220     in PCRE is for the caller to provide an optional function, by setting
2221     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2222     global variable. By default it is unset, which disables all calling out. To get
2223     the function called, the regex must include (?C) at appropriate points. This
2224     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2225     This provides a means of identifying different callout points. When PCRE
2226     reaches such a point in the regex, if pcre_callout has been set, the external
2227     function is called. It is provided with data in a structure called
2228     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2229     matching continues; if it returns a non-zero value, the match at the current
2230     point fails. However, backtracking will occur if possible. [This was changed
2231     later and other features added - see item 49 below.]
2233     29. pcretest is upgraded to test the callout functionality. It provides a
2234     callout function that displays information. By default, it shows the start of
2235     the match and the current position in the text. There are some new data escapes
2236     to vary what happens:
2238     \C+ in addition, show current contents of captured substrings
2239     \C- do not supply a callout function
2240     \C!n return 1 when callout number n is reached
2241     \C!n!m return 1 when callout number n is reached for the mth time
2243     30. If pcregrep was called with the -l option and just a single file name, it
2244     output "<stdin>" if a match was found, instead of the file name.
2246     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2247     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2248     pcre_exec(). This saves a malloc/free per call. The default value of
2249     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2250     when configuring.
2252     32. The default maximum size of a compiled pattern is 64K. There have been a
2253     few cases of people hitting this limit. The code now uses macros to handle the
2254     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2255     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2256     configuring. Tests 2 and 5 work only with 2-byte links because they output
2257     debugging information about compiled patterns.
2259     33. Internal code re-arrangements:
2261     (a) Moved the debugging function for printing out a compiled regex into
2262     its own source file (printint.c) and used #include to pull it into
2263     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2264     separate copies.
2266     (b) Defined the list of op-code names for debugging as a macro in
2267     internal.h so that it is next to the definition of the opcodes.
2269     (c) Defined a table of op-code lengths for simpler skipping along compiled
2270     code. This is again a macro in internal.h so that it is next to the
2271     definition of the opcodes.
2273     34. Added support for recursive calls to individual subpatterns, along the
2274     lines of Robin Houston's patch (but implemented somewhat differently).
2276     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2277     allow it to read and process whole directories in Win32. This code was
2278     contributed by Lionel Fourquaux; it has not been tested by me.
2280     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2281     used to name a group. Names consist of alphanumerics and underscores, and must
2282     be unique. Back references use the syntax (?P=name) and recursive calls use
2283     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2284     numbers. The function pcre_fullinfo() can be used after compilation to extract
2285     a name/number map. There are three relevant calls:
2287     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2288     PCRE_INFO_NAMECOUNT yields the number of entries
2289     PCRE_INFO_NAMETABLE yields a pointer to the map.
2291     The map is a vector of fixed-size entries. The size of each entry depends on
2292     the length of the longest name used. The first two bytes of each entry are the
2293     group number, most significant byte first. There follows the corresponding
2294     name, zero terminated. The names are in alphabetical order.
2296     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2297     case instead of 255. Making it the same both with and without UTF-8 support
2298     means that the same test output works with both.
2300     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2301     calling malloc() with a zero argument.
2303     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2304     optimization. I've improved things by keeping a bitmap of backreferences with
2305     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2306     fact referenced, the optimization can be applied. It is unlikely that a
2307     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2308     the match to follow \n) will appear inside brackets with a number greater than
2309     31, but if it does, any back reference > 31 suppresses the optimization.
2311     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2312     of disabling numbered capturing parentheses. Any opening parenthesis that is
2313     not followed by ? behaves as if it were followed by ?: but named parentheses
2314     can still be used for capturing (and they will acquire numbers in the usual
2315     way).
2317     41. Redesigned the return codes from the match() function into yes/no/error so
2318     that errors can be passed back from deep inside the nested calls. A malloc
2319     failure while inside a recursive subpattern call now causes the
2320     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2322     42. It is now possible to set a limit on the number of times the match()
2323     function is called in a call to pcre_exec(). This facility makes it possible to
2324     limit the amount of recursion and backtracking, though not in a directly
2325     obvious way, because the match() function is used in a number of different
2326     circumstances. The count starts from zero for each position in the subject
2327     string (for non-anchored patterns). The default limit is, for compatibility, a
2328     large number, namely 10 000 000. You can change this in two ways:
2330     (a) When configuring PCRE before making, you can use --with-match-limit=n
2331     to set a default value for the compiled library.
2333     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2334     a different value is set. See 45 below.
2336     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2338     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2339     of things that can be changed at compile time. The first argument specifies
2340     what is wanted and the second points to where the information is to be placed.
2341     The current list of available information is:
2345     The output is an integer that is set to one if UTF-8 support is available;
2346     otherwise it is set to zero.
2350     The output is an integer that it set to the value of the code that is used for
2351     newline. It is either LF (10) or CR (13).
2355     The output is an integer that contains the number of bytes used for internal
2356     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2360     The output is an integer that contains the threshold above which the POSIX
2361     interface uses malloc() for output vectors. See item 31 above.
2365     The output is an unsigned integer that contains the default limit of the number
2366     of match() calls in a pcre_exec() execution. See 42 above.
2368     44. pcretest has been upgraded by the addition of the -C option. This causes it
2369     to extract all the available output from the new pcre_config() function, and to
2370     output it. The program then exits immediately.
2372     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2373     order to support additional features. One way would have been to define
2374     pcre_exec2() (for example) with extra arguments, but this would not have been
2375     extensible, and would also have required all calls to the original function to
2376     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2377     is used for passing in "extra" data from pcre_study().
2379     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2380     contains the following fields:
2382     flags a bitmap indicating which of the following fields are set
2383     study_data opaque data from pcre_study()
2384     match_limit a way of specifying a limit on match() calls for a specific
2385     call to pcre_exec()
2386     callout_data data for callouts (see 49 below)
2388     The flag bits are also defined in pcre.h, and are
2394     The pcre_study() function now returns one of these new pcre_extra blocks, with
2395     the actual study data pointed to by the study_data field, and the
2396     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2397     before. That is, this change is entirely upwards-compatible and requires no
2398     change to existing code.
2400     If you want to pass in additional data to pcre_exec(), you can either place it
2401     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2402     block.
2404     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2405     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2406     times with different match limits, until it finds the minimum value needed for
2407     pcre_exec() to complete. The value is then output. This can be instructive; for
2408     most simple matches the number is quite small, but for pathological cases it
2409     gets very large very quickly.
2411     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2412     returns the size of the data block pointed to by the study_data field in a
2413     pcre_extra block, that is, the value that was passed as the argument to
2414     pcre_malloc() when PCRE was getting memory in which to place the information
2415     created by pcre_study(). The fourth argument should point to a size_t variable.
2416     pcretest has been extended so that this information is shown after a successful
2417     pcre_study() call when information about the compiled regex is being displayed.
2419     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2420     because what follows is always an absolute path. (Later: it turns out that this
2421     is more than cosmetic for MinGW, because it doesn't like empty path
2422     components.)
2424     49. Some changes have been made to the callout feature (see 28 above):
2426     (i) A callout function now has three choices for what it returns:
2428     0 => success, carry on matching
2429     > 0 => failure at this point, but backtrack if possible
2430     < 0 => serious error, return this value from pcre_exec()
2432     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2433     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2434     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2435     use by callout functions. It will never be used by PCRE itself.
2437     (ii) The pcre_extra structure (see 45 above) has a void * field called
2438     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2439     pcre_callout_block structure has a field of the same name. The contents of
2440     the field passed in the pcre_extra structure are passed to the callout
2441     function in the corresponding field in the callout block. This makes it
2442     easier to use the same callout-containing regex from multiple threads. For
2443     testing, the pcretest program has a new data escape
2445     \C*n pass the number n (may be negative) as callout_data
2447     If the callout function in pcretest receives a non-zero value as
2448     callout_data, it returns that value.
2450     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2451     there were some redundant $(CFLAGS) in commands that are now specified as
2452     $(LINK), which already includes $(CFLAGS).
2454     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2455     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2456     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2457     one-byte characters throughout. Note that case-insensitive matching applies
2458     only to characters whose values are less than 256. PCRE doesn't support the
2459     notion of cases for higher-valued characters.
2461     (i) A character class whose characters are all within 0-255 is handled as
2462     a bit map, and the map is inverted for negative classes. Previously, a
2463     character > 255 always failed to match such a class; however it should
2464     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2466     (ii) A negated character class with a single character < 255 is coded as
2467     "not this character" (OP_NOT). This wasn't working properly when the test
2468     character was multibyte, either singly or repeated.
2470     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2471     mode, for example: \x{100}{2,3}.
2473     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2474     singly or repeated) now correctly test multibyte characters. However,
2475     PCRE doesn't recognize any characters with values greater than 255 as
2476     digits, spaces, or word characters. Such characters always match \D, \S,
2477     and \W, and never match \d, \s, or \w.
2479     (v) Classes may now contain characters and character ranges with values
2480     greater than 255. For example: [ab\x{100}-\x{400}].
2482     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2483     PCRE in UTF-8 mode.
2485     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2486     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2487     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2488     value.)
2490     53. The single man page has become too large. I have therefore split it up into
2491     a number of separate man pages. These also give rise to individual HTML pages;
2492     these are now put in a separate directory, and there is an index.html page that
2493     lists them all. Some hyperlinking between the pages has been installed.
2495     54. Added convenience functions for handling named capturing parentheses.
2497     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2498     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2499     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2500     are faulted.
2502     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2503     calling configure. These values are used when compiling the dftables.c program
2504     which is run to generate the source of the default character tables. They
2505     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2506     you will need to set these values.
2508     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2511     Version 3.9 02-Jan-02
2512 nigel 61 ---------------------
2514     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2516     2. If --disable-static was given, the building process failed when trying to
2517     build pcretest and pcregrep. (For some reason it was using libtool to compile
2518     them, which is not right, as they aren't part of the library.)
2521 nigel 59 Version 3.8 18-Dec-01
2522     ---------------------
2524     1. The experimental UTF-8 code was completely screwed up. It was packing the
2525     bytes in the wrong order. How dumb can you get?
2528 nigel 57 Version 3.7 29-Oct-01
2529     ---------------------
2531     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2532     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2533     this didn't happen under Solaris 8, where I normally test things.
2535 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2536     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2537     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2538     this fix an hour or so after the initial 3.7 release.)
2539 nigel 57
2540 nigel 59
2541 nigel 55 Version 3.6 23-Oct-01
2542     ---------------------
2544     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2545     offsets passed as NULL with zero offset count.
2547     2. The config.guess and config.sub files had not been updated when I moved to
2548     the latest autoconf.
2551 nigel 53 Version 3.5 15-Aug-01
2552     ---------------------
2553 nigel 5
2554 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2555     had been forgotten.
2557     2. By using declared but undefined structures, we can avoid using "void"
2558     definitions in pcre.h while keeping the internal definitions of the structures
2559     private.
2561     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2562     user point of view, this means that both static and shared libraries are built
2563     by default, but this can be individually controlled. More of the work of
2564     handling this static/shared cases is now inside libtool instead of PCRE's make
2565     file.
2567     4. The pcretest utility is now installed along with pcregrep because it is
2568     useful for users (to test regexs) and by doing this, it automatically gets
2569     relinked by libtool. The documentation has been turned into a man page, so
2570     there are now .1, .txt, and .html versions in /doc.
2572     5. Upgrades to pcregrep:
2573     (i) Added long-form option names like gnu grep.
2574     (ii) Added --help to list all options with an explanatory phrase.
2575     (iii) Added -r, --recursive to recurse into sub-directories.
2576     (iv) Added -f, --file to read patterns from a file.
2578     6. pcre_exec() was referring to its "code" argument before testing that
2579     argument for NULL (and giving an error if it was NULL).
2581     7. Upgraded Makefile.in to allow for compiling in a different directory from
2582     the source directory.
2584     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2585     options bits, the pointer it was passed was to an int instead of to an unsigned
2586     long int. This mattered only on 64-bit systems.
2588     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2589     generated) instead of pcre.in, which it its source. Also made the same change
2590     in several of the .c files.
2592     10. A new release of gcc defines printf() as a macro, which broke pcretest
2593     because it had an ifdef in the middle of a string argument for printf(). Fixed
2594     by using separate calls to printf().
2596     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2597     script, to force use of CR or LF instead of \n in the source. On non-Unix
2598     systems, the value can be set in config.h.
2600     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2601     absolute limit. Changed the text of the error message to make this clear, and
2602     likewise updated the man page.
2604     13. The limit of 99 on the number of capturing subpatterns has been removed.
2605     The new limit is 65535, which I hope will not be a "real" limit.
2608 nigel 51 Version 3.4 22-Aug-00
2609     ---------------------
2611     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2613     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2616 nigel 49 Version 3.3 01-Aug-00
2617     ---------------------
2619     1. If an octal character was given, but the value was greater than \377, it
2620     was not getting masked to the least significant bits, as documented. This could
2621     lead to crashes in some systems.
2623     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2624     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2626     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2627     These just pass their arguments on to (pcre_free)(), but they are provided
2628     because some uses of PCRE bind it to non-C systems that can call its functions,
2629     but cannot call free() or pcre_free() directly.
2631     4. Add "make test" as a synonym for "make check". Corrected some comments in
2632     the Makefile.
2634     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2635     Makefile.
2637     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2638     command called pgrep for grepping around the active processes.
2640     7. Added the beginnings of support for UTF-8 character strings.
2642     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2643     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2644     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2645     out for the ar command.)
2648 nigel 47 Version 3.2 12-May-00
2649     ---------------------
2651     This is purely a bug fixing release.
2653     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2654     of ZA. This was just one example of several cases that could provoke this bug,
2655     which was introduced by change 9 of version 2.00. The code for breaking
2656     infinite loops after an iteration that matches an empty string was't working
2657     correctly.
2659     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2660     when matched against abbab (for example). After matching an empty string, it
2661     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2662     caused it to match further down the string than it should.
2664     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2665     was there because it doesn't seem to be needed, and it causes trouble on some
2666     systems, as it is not a Standard C header. It has been removed.
2668     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2669     were reported on the Macintosh. The changes were from
2671     while ((c = *(++ptr)) != 0 && c != '\n');
2672     to
2673     while ((c = *(++ptr)) != 0 && c != '\n') ;
2675     Totally extraordinary, but if that's what it takes...
2677     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2678     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2679     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2680     assumes the way PCRE uses memmove() (always moving upwards).
2682     6. PCRE is being used in one environment where strchr() is not available. There
2683     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2684     faster code anyway.
2687 nigel 45 Version 3.1 09-Feb-00
2688     ---------------------
2690     The only change in this release is the fixing of some bugs in Makefile.in for
2691     the "install" target:
2693     (1) It was failing to install pcreposix.h.
2695     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2698 nigel 43 Version 3.0 01-Feb-00
2699     ---------------------
2700 nigel 41
2701     1. Add support for the /+ modifier to perltest (to output $` like it does in
2702     pcretest).
2704     2. Add support for the /g modifier to perltest.
2706     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2707     matches null strings.
2709     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2710     pattern. Perl treats empty patterns specially - it reuses the most recent
2711     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2712     effect.
2714     5. The POSIX interface was broken in that it was just handing over the POSIX
2715     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2716     required a bigger vector, with some working space on the end. This means that
2717     the POSIX wrapper now has to get and free some memory, and copy the results.
2719 nigel 43 6. Added some simple autoconf support, placing the test data and the
2720     documentation in separate directories, re-organizing some of the
2721     information files, and making it build pcre-config (a GNU standard). Also added
2722     libtool support for building PCRE as a shared library, which is now the
2723     default.
2724 nigel 41
2725 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2726     09 are not valid octal constants. Single digits will be used for minor values
2727     less than 10.
2729     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2730     existing programs that set these in the POSIX interface can use PCRE without
2731     modification.
2733     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2734     return all that pcre_info() returns, plus additional data. The pcre_info()
2735     function is retained for compatibility, but is considered to be obsolete.
2737     10. Added experimental recursion feature (?R) to handle one common case that
2738     Perl 5.6 will be able to do with (?p{...}).
2740     11. Added support for POSIX character classes like [:alpha:], which Perl is
2741     adopting.
2744 nigel 39 Version 2.08 31-Aug-99
2745     ----------------------
2747     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2748     trying to match at the startoffset position, but instead was moving forward to
2749     the next newline as if a previous match had failed.
2751     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2752     and could get into a loop if a null string was matched other than at the start
2753     of the subject.
2755     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2756     be distinguished at compile time, and for completeness also added PCRE_DATE.
2758     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2759     in GnuWin32 environments.
2762 nigel 37 Version 2.07 29-Jul-99
2763     ----------------------
2765     1. The documentation is now supplied in plain text form and HTML as well as in
2766     the form of man page sources.
2768     2. C++ compilers don't like assigning (void *) values to other pointer types.
2769     In particular this affects malloc(). Although there is no problem in Standard
2770     C, I've put in casts to keep C++ compilers happy.
2772     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2773     should be (const char *).
2775     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2776     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2777     However, I haven't made this a standard facility. The documentation doesn't
2778     mention it, and the Makefile doesn't support it.
2780     5. The Makefile now contains an "install" target, with editable destinations at
2781     the top of the file. The pcretest program is not installed.
2783     6. pgrep -V now gives the PCRE version number and date.
2785     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2786     causing the entire string to be ignored, instead of just the last character.
2788     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2789     non-matching string, it can take a very, very long time, even for strings of
2790     quite modest length, because of the nested recursion. PCRE now does better in
2791     some of these cases. It does this by remembering the last required literal
2792     character in the pattern, and pre-searching the subject to ensure it is present
2793     before running the real match. In other words, it applies a heuristic to detect
2794     some types of certain failure quickly, and in the above example, if presented
2795     with a string that has no trailing " it gives "no match" very quickly.
2797     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2798     other alternatives are tried instead.
2801 nigel 35 Version 2.06 09-Jun-99
2802     ----------------------
2804     1. Change pcretest's output for amount of store used to show just the code
2805     space, because the remainder (the data block) varies in size between 32-bit and
2806     64-bit systems.
2808     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2809     start matching at. This allows lookbehinds to work when searching for multiple
2810     occurrences in a string.
2812     3. Added additional options to pcretest for testing multiple occurrences:
2814     /+ outputs the rest of the string that follows a match
2815     /g loops for multiple occurrences, using the new startoffset argument
2816     /G loops for multiple occurrences by passing an incremented pointer
2818     4. PCRE wasn't doing the "first character" optimization for patterns starting
2819     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2820     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2821     the letter 'x'. On long subject strings, this gives a significant speed-up.
2824 nigel 33 Version 2.05 21-Apr-99
2825     ----------------------
2827     1. Changed the type of magic_number from int to long int so that it works
2828     properly on 16-bit systems.
2830     2. Fixed a bug which caused patterns starting with .* not to work correctly
2831     when the subject string contained newline characters. PCRE was assuming
2832     anchoring for such patterns in all cases, which is not correct because .* will
2833     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2834     DOTALL is set at top level; otherwise it knows that patterns starting with .*
2835     must be retried after every newline in the subject.
2838 nigel 31 Version 2.04 18-Feb-99
2839     ----------------------
2841     1. For parenthesized subpatterns with repeats whose minimum was zero, the
2842     computation of the store needed to hold the pattern was incorrect (too large).
2843     If such patterns were nested a few deep, this could multiply and become a real
2844     problem.
2846     2. Added /M option to pcretest to show the memory requirement of a specific
2847     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2849     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2850     compiled in such a way that the backtracking after subsequent failure was
2851     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2852     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2855 nigel 29 Version 2.03 02-Feb-99
2856     ----------------------
2858     1. Fixed typo and small mistake in man page.
2860 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
2861     LICENCE file containing the conditions.
2862 nigel 29
2863     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2864     Perl, that is the internal \ allows the delimiter to be included in the
2865     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2866     the final delimiter, add \ to the end of the pattern (to test the error).
2868     4. Added the convenience functions for extracting substrings after a successful
2869     match. Updated pcretest to make it able to test these functions.
2872 nigel 27 Version 2.02 14-Jan-99
2873     ----------------------
2875     1. Initialized the working variables associated with each extraction so that
2876     their saving and restoring doesn't refer to uninitialized store.
2878     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2879     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2880     fix the problem.
2882     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2883     calls, and wasn't printing the correct value for compiling calls. Increased the
2884     default value of LOOPREPEAT, and the number of significant figures in the
2885     times.
2887     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2889     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2890     a building problem on Windows NT with a FAT file system.
2893 nigel 25 Version 2.01 21-Oct-98
2894     ----------------------
2896     1. Changed the API for pcre_compile() to allow for the provision of a pointer
2897     to character tables built by pcre_maketables() in the current locale. If NULL
2898     is passed, the default tables are used.
2901 nigel 23 Version 2.00 24-Sep-98
2902 nigel 21 ----------------------
2904 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2905     it any more.
2907     2. Allow quantification of (?>) groups, and make it work correctly.
2909     3. The first character computation wasn't working for (?>) groups.
2911     4. Correct the implementation of \Z (it is permitted to match on the \n at the
2912     end of the subject) and add 5.005's \z, which really does match only at the
2913     very end of the subject.
2915     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2917     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2918     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2919     localized options. All options to pcre_study() were also removed.
2921     7. Add other new features from 5.005:
2923     $(?<= positive lookbehind
2924     $(?<! negative lookbehind
2925     (?imsx-imsx) added the unsetting capability
2926     such a setting is global if at outer level; local otherwise
2927     (?imsx-imsx:) non-capturing groups with option setting
2928     (?(cond)re|re) conditional pattern matching
2930     A backreference to itself in a repeated group matches the previous
2931     captured string.
2933     8. General tidying up of studying (both automatic and via "study")
2934     consequential on the addition of new assertions.
2936     9. As in 5.005, unlimited repeated groups that could match an empty substring
2937     are no longer faulted at compile time. Instead, the loop is forcibly broken at
2938     runtime if any iteration does actually match an empty substring.
2940     10. Include the RunTest script in the distribution.
2942     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2943     discrepancies, some of which were old and were also with respect to 5.004. They
2944     have now been fixed.
2947     Version 1.09 28-Apr-98
2948     ----------------------
2950 nigel 21 1. A negated single character class followed by a quantifier with a minimum
2951     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2952     program crashes, or just wrong answers. This did not apply to negated classes
2953     containing more than one character, or to minima other than one.
2956 nigel 19 Version 1.08 27-Mar-98
2957     ----------------------
2959     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2961     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2962     latter must appear before anything that relies on it in the pattern.
2965 nigel 17 Version 1.07 16-Feb-98
2966     ----------------------
2968     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2969     repeat of a potentially empty string).
2972 nigel 15 Version 1.06 23-Jan-98
2973     ----------------------
2975     1. Added Markus Oberhumer's little patches for C++.
2977     2. Literal strings longer than 255 characters were broken.
2980 nigel 13 Version 1.05 23-Dec-97
2981     ----------------------
2983     1. Negated character classes containing more than one character were failing if
2984     PCRE_CASELESS was set at run time.
2987 nigel 11 Version 1.04 19-Dec-97
2988     ----------------------
2990     1. Corrected the man page, where some "const" qualifiers had been omitted.
2992     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
2993     input syntax.
2995     3. Fixed memory leak which occurred when a regex with back references was
2996     matched with an offsets vector that wasn't big enough. The temporary memory
2997     that is used in this case wasn't being freed if the match failed.
2999     4. Tidied pcretest to ensure it frees memory that it gets.
3001     5. Temporary memory was being obtained in the case where the passed offsets
3002     vector was exactly big enough.
3004     6. Corrected definition of offsetof() from change 5 below.
3006     7. I had screwed up change 6 below and broken the rules for the use of
3007     setjmp(). Now fixed.
3010 nigel 9 Version 1.03 18-Dec-97
3011     ----------------------
3013     1. A erroneous regex with a missing opening parenthesis was correctly
3014     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3015     on some systems.
3017     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3018     it was reported that one broken compiler failed on the former because "code" is
3019     also an independent variable.
3021     3. The erroneous regex a[]b caused an array overrun reference.
3023     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3024     fail on data ending with that character. (It was going on too far, and checking
3025     the next character, typically a binary zero.) This was specific to the
3026     optimized code for single-character negative classes.
3028     5. Added a contributed patch from the TIN world which does the following:
3030     + Add an undef for memmove, in case the the system defines a macro for it.
3032     + Add a definition of offsetof(), in case there isn't one. (I don't know
3033     the reason behind this - offsetof() is part of the ANSI standard - but
3034     it does no harm).
3036     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3037     most of the places where whitespace preceded '#'. I have given up and
3038     allowed the remaining 2 cases to be at the margin.
3040     + Rename some variables in pcre to eliminate shadowing. This seems very
3041     pedantic, but does no harm, of course.
3043     6. Moved the call to setjmp() into its own function, to get rid of warnings
3044     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3046     7. Constructs such as \d{8,} were compiling into the equivalent of
3047 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3048 nigel 9 outcome, but in this particular case used more store than had been allocated,
3049     which caused the bug to be discovered because it threw up an internal error.
3051     8. The debugging code in both pcre and pcretest for outputting the compiled
3052     form of a regex was going wrong in the case of back references followed by
3053     curly-bracketed repeats.
3056 nigel 7 Version 1.02 12-Dec-97
3057     ----------------------
3059     1. Typos in pcre.3 and comments in the source fixed.
3061     2. Applied a contributed patch to get rid of places where it used to remove
3062     'const' from variables, and fixed some signed/unsigned and uninitialized
3063     variable warnings.
3065     3. Added the "runtest" target to Makefile.
3067     4. Set default compiler flag to -O2 rather than just -O.
3070 nigel 5 Version 1.01 19-Nov-97
3071     ----------------------
3073     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3074     like /([ab]*)*/, that is, for classes with more than one character in them.
3076     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3077     as /((?>a*))*/ (a PCRE_EXTRA facility).
3080     Version 1.00 18-Nov-97
3081     ----------------------
3083     1. Added compile-time macros to support systems such as SunOS4 which don't have
3084     memmove() or strerror() but have other things that can be used instead.
3086     2. Arranged that "make clean" removes the executables.
3089 nigel 3 Version 0.99 27-Oct-97
3090     ----------------------
3092     1. Fixed bug in code for optimizing classes with only one character. It was
3093     initializing a 32-byte map regardless, which could cause it to run off the end
3094     of the memory it had got.
3096     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3099     Version 0.98 22-Oct-97
3100     ----------------------
3102     1. Fixed bug in code for handling temporary memory usage when there are more
3103     back references than supplied space in the ovector. This could cause segfaults.
3106     Version 0.97 21-Oct-97
3107     ----------------------
3109     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3111     2. Optimized negated single characters not to use a bit map.
3113     3. Brought error texts together as macro definitions; clarified some of them;
3114     fixed one that was wrong - it said "range out of order" when it meant "invalid
3115     escape sequence".
3117     4. Changed some char * arguments to const char *.
3119     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3121     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3122     pcretest.
3125     Version 0.96 16-Oct-97
3126     ----------------------
3128     1. Added a simple "pgrep" utility to the distribution.
3130     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3131     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3132     where "ddd" means "one or more decimal digits".
3134     3. Fixed serious bug. If a pattern had a back reference, but the call to
3135     pcre_exec() didn't supply a large enough ovector to record the related
3136     identifying subpattern, the match always failed. PCRE now remembers the number
3137     of the largest back reference, and gets some temporary memory in which to save
3138     the offsets during matching if necessary, in order to ensure that
3139     backreferences always work.
3141     4. Increased the compatibility with Perl in a number of ways:
3143     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3144     to request this handling. The option can be set at compile or exec time.
3146     (b) $ matches before a terminating newline by default; an option
3147     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3148     mode). The option can be set at compile or exec time.
3150     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3151     the same as Perl's. If the decimal number it represents is less than 10
3152     or there aren't that many previous left capturing parentheses, an octal
3153     escape is read. Inside a character class, it's always an octal escape,
3154     even if it is a single digit.
3156     (d) An escaped but undefined alphabetic character is taken as a literal,
3157     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3158     escapes.
3160     (e) {0} is now permitted. (The previous item is removed from the compiled
3161     pattern).
3163     5. Changed all the names of code files so that the basic parts are no longer
3164     than 10 characters, and abolished the teeny "globals.c" file.
3166     6. Changed the handling of character classes; they are now done with a 32-byte
3167     bit map always.
3169     7. Added the -d and /D options to pcretest to make it possible to look at the
3170     internals of compilation without having to recompile pcre.
3173     Version 0.95 23-Sep-97
3174     ----------------------
3176     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3177     \x20 at the start of a run of normal characters. These were being treated as
3178     real characters, instead of the source characters being re-checked.
3181     Version 0.94 18-Sep-97
3182     ----------------------
3184     1. The functions are now thread-safe, with the caveat that the global variables
3185     containing pointers to malloc() and free() or alternative functions are the
3186     same for all threads.
3188     2. Get pcre_study() to generate a bitmap of initial characters for non-
3189     anchored patterns when this is possible, and use it if passed to pcre_exec().
3192     Version 0.93 15-Sep-97
3193     ----------------------
3195     1. /(b)|(:+)/ was computing an incorrect first character.
3197     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3198     but not actually doing anything yet.
3200     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3201     as Perl does (e.g. [-az] or [az-]).
3203     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3204     all possible positions.
3206     5. Split up into different modules to avoid including unneeded functions in a
3207     compiled binary. However, compile and exec are still in one module. The "study"
3208     function is split off.
3210     6. The character tables are now in a separate module whose source is generated
3211     by an auxiliary program - but can then be edited by hand if required. There are
3212     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3213     toupper() in the code.
3215     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3216     make them global. Abolish the function for setting them, as the caller can now
3217     set them directly.
3220     Version 0.92 11-Sep-97
3221     ----------------------
3223     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3224     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3226     2. Caseless matching was not working in character classes if the characters in
3227     the pattern were in upper case.
3229     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3231     4. Make PCRE_ANCHORED public and accept as a compile option.
3233     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3234     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3235     pass them.
3237     6. Give an error if bad option bits passed at compile or run time.
3239     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3240     pcretest to cause it to pass that flag.
3242     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3243     options, and the first character, if set.
3245     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3248     Version 0.91 10-Sep-97
3249     ----------------------
3251     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3252     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3254     2. PCRE was looping on encountering an indefinitely repeated back reference to
3255     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3256     Perl does - treats the match as successful.
3258     ****


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