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ChangeLog for PCRE |
ChangeLog for PCRE |
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Version 8.00 ??-???-?? |
Version 8.01 11-Dec-09 |
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1. The table for translating pcre_compile() error codes into POSIX error codes |
1. If a pattern contained a conditional subpattern with only one branch (in |
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was out-of-date, and there was no check on the pcre_compile() error code |
particular, this includes all (DEFINE) patterns), a call to pcre_study() |
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being within the table. This could lead to an OK return being given in |
computed the wrong minimum data length (which is of course zero for such |
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error. |
subpatterns). |
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2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of |
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the pattern is reset in the first branch, pcre_compile() failed with |
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"internal error: code overflow at offset...". This happened only when |
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the reset was to the original external option setting. (An optimization |
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abstracts leading options settings into an external setting, which was the |
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cause of this.) |
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3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one |
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of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the |
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assertion pattern did not match (meaning that the assertion was true), it |
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was incorrectly treated as false if the SKIP had been reached during the |
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matching. This also applied to assertions used as conditions. |
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4. If an item that is not supported by pcre_dfa_exec() was encountered in an |
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assertion subpattern, including such a pattern used as a condition, |
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unpredictable results occurred, instead of the error return |
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PCRE_ERROR_DFA_UITEM. |
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5. The C++ GlobalReplace function was not working like Perl for the special |
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situation when an empty string is matched. It now does the fancy magic |
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stuff that is necessary. |
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6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been |
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removed. (These were left over from very, very early versions of PCRE.) |
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7. Some cosmetic changes to the code to make life easier when compiling it |
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as part of something else: |
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(a) Change DEBUG to PCRE_DEBUG. |
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(b) In pcre_compile(), rename the member of the "branch_chain" structure |
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called "current" as "current_branch", to prevent a collision with the |
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Linux macro when compiled as a kernel module. |
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(c) In pcre_study(), rename the function set_bit() as set_table_bit(), to |
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prevent a collision with the Linux macro when compiled as a kernel |
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module. |
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8. In pcre_compile() there are some checks for integer overflows that used to |
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cast potentially large values to (double). This has been changed to that |
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when building, a check for int64_t is made, and if it is found, it is used |
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instead, thus avoiding the use of floating point arithmetic. (There is no |
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other use of FP in PCRE.) If int64_t is not found, the fallback is to |
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double. |
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9. Added two casts to avoid signed/unsigned warnings from VS Studio Express |
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2005 (difference between two addresses compared to an unsigned value). |
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10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a |
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custom one, because of the following reported problem in Windows: |
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- libbz2 uses the Pascal calling convention (WINAPI) for the functions |
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under Win32. |
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- The standard autoconf AC_CHECK_LIB fails to include "bzlib.h", |
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therefore missing the function definition. |
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- The compiler thus generates a "C" signature for the test function. |
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- The linker fails to find the "C" function. |
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- PCRE fails to configure if asked to do so against libbz2. |
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11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these |
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messages were output: |
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Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and |
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rerunning libtoolize, to keep the correct libtool macros in-tree. |
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Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am. |
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I have done both of these things. |
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2. Changed the call to open a subject file in pcregrep from fopen(pathname, |
12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec() |
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"r") to fopen(pathname, "rb"), which fixed a problem with some of the tests |
most of the time, it *can* run out if it is given a pattern that contains a |
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in a Windows environment. |
runaway infinite recursion. I updated the discussion in the pcrestack man |
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page. |
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13. Now that we have gone to the x.xx style of version numbers, the minor |
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version may start with zero. Using 08 or 09 is a bad idea because users |
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might check the value of PCRE_MINOR in their code, and 08 or 09 may be |
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interpreted as invalid octal numbers. I've updated the previous comment in |
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configure.ac, and also added a check that gives an error if 08 or 09 are |
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used. |
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Version 8.00 19-Oct-09 |
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---------------------- |
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1. The table for translating pcre_compile() error codes into POSIX error codes |
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was out-of-date, and there was no check on the pcre_compile() error code |
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being within the table. This could lead to an OK return being given in |
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error. |
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2. Changed the call to open a subject file in pcregrep from fopen(pathname, |
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"r") to fopen(pathname, "rb"), which fixed a problem with some of the tests |
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in a Windows environment. |
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3. The pcregrep --count option prints the count for each file even when it is |
3. The pcregrep --count option prints the count for each file even when it is |
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zero, as does GNU grep. However, pcregrep was also printing all files when |
zero, as does GNU grep. However, pcregrep was also printing all files when |
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--files-with-matches was added. Now, when both options are given, it prints |
--files-with-matches was added. Now, when both options are given, it prints |
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counts only for those files that have at least one match. (GNU grep just |
counts only for those files that have at least one match. (GNU grep just |
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prints the file name in this circumstance, but including the count seems |
prints the file name in this circumstance, but including the count seems |
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more useful - otherwise, why use --count?) Also ensured that the |
more useful - otherwise, why use --count?) Also ensured that the |
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combination -clh just lists non-zero counts, with no names. |
combination -clh just lists non-zero counts, with no names. |
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4. The long form of the pcregrep -F option was incorrectly implemented as |
4. The long form of the pcregrep -F option was incorrectly implemented as |
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--fixed_strings instead of --fixed-strings. This is an incompatible change, |
--fixed_strings instead of --fixed-strings. This is an incompatible change, |
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but it seems right to fix it, and I didn't think it was worth preserving |
but it seems right to fix it, and I didn't think it was worth preserving |
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the old behaviour. |
the old behaviour. |
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5. The command line items --regex=pattern and --regexp=pattern were not |
5. The command line items --regex=pattern and --regexp=pattern were not |
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recognized by pcregrep, which required --regex pattern or --regexp pattern |
recognized by pcregrep, which required --regex pattern or --regexp pattern |
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(with a space rather than an '='). The man page documented the '=' forms, |
(with a space rather than an '='). The man page documented the '=' forms, |
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which are compatible with GNU grep; these now work. |
which are compatible with GNU grep; these now work. |
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6. No libpcreposix.pc file was created for pkg-config; there was just |
6. No libpcreposix.pc file was created for pkg-config; there was just |
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libpcre.pc and libpcrecpp.pc. The omission has been rectified. |
libpcre.pc and libpcrecpp.pc. The omission has been rectified. |
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7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size |
7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size |
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when UCP support is not needed, by modifying the Python script that |
when UCP support is not needed, by modifying the Python script that |
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generates it from Unicode data files. This should not matter if the module |
generates it from Unicode data files. This should not matter if the module |
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is correctly used as a library, but I received one complaint about 50K of |
is correctly used as a library, but I received one complaint about 50K of |
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unwanted data. My guess is that the person linked everything into his |
unwanted data. My guess is that the person linked everything into his |
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program rather than using a library. Anyway, it does no harm. |
program rather than using a library. Anyway, it does no harm. |
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8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger |
8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger |
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was a minimum greater than 1 for a wide character in a possessive |
was a minimum greater than 1 for a wide character in a possessive |
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repetition. Chaos could result. |
repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8 |
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which had an unlimited repeat of a nested, fixed maximum repeat of a wide |
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character. Chaos in the form of incorrect output or a compiling loop could |
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result. |
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9. The restrictions on what a pattern can contain when partial matching is |
9. The restrictions on what a pattern can contain when partial matching is |
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requested for pcre_exec() have been removed. All patterns can now be |
requested for pcre_exec() have been removed. All patterns can now be |
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partially matched by this function. In addition, if there are at least two |
partially matched by this function. In addition, if there are at least two |
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slots in the offset vector, the offsets of the first-encountered partial |
slots in the offset vector, the offset of the earliest inspected character |
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match are set in them when PCRE_ERROR_PARTIAL is returned. |
for the match and the offset of the end of the subject are set in them when |
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PCRE_ERROR_PARTIAL is returned. |
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10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is |
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synonymous with PCRE_PARTIAL, for backwards compatibility, and |
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PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match, |
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and may be more useful for multi-segment matching. |
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11. Partial matching with pcre_exec() is now more intuitive. A partial match |
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used to be given if ever the end of the subject was reached; now it is |
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given only if matching could not proceed because another character was |
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needed. This makes a difference in some odd cases such as Z(*FAIL) with the |
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string "Z", which now yields "no match" instead of "partial match". In the |
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case of pcre_dfa_exec(), "no match" is given if every matching path for the |
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final character ended with (*FAIL). |
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12. Restarting a match using pcre_dfa_exec() after a partial match did not work |
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if the pattern had a "must contain" character that was already found in the |
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earlier partial match, unless partial matching was again requested. For |
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example, with the pattern /dog.(body)?/, the "must contain" character is |
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"g". If the first part-match was for the string "dog", restarting with |
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"sbody" failed. This bug has been fixed. |
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13. The string returned by pcre_dfa_exec() after a partial match has been |
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changed so that it starts at the first inspected character rather than the |
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first character of the match. This makes a difference only if the pattern |
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starts with a lookbehind assertion or \b or \B (\K is not supported by |
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pcre_dfa_exec()). It's an incompatible change, but it makes the two |
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matching functions compatible, and I think it's the right thing to do. |
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14. Added a pcredemo man page, created automatically from the pcredemo.c file, |
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so that the demonstration program is easily available in environments where |
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PCRE has not been installed from source. |
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15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp, |
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libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared |
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library. |
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16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user. |
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It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it |
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is not the first non-POSIX option to be added. Clearly some people find |
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these options useful. |
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17. If a caller to the POSIX matching function regexec() passes a non-zero |
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value for nmatch with a NULL value for pmatch, the value of |
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nmatch is forced to zero. |
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18. RunGrepTest did not have a test for the availability of the -u option of |
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the diff command, as RunTest does. It now checks in the same way as |
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RunTest, and also checks for the -b option. |
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19. If an odd number of negated classes containing just a single character |
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interposed, within parentheses, between a forward reference to a named |
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subpattern and the definition of the subpattern, compilation crashed with |
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an internal error, complaining that it could not find the referenced |
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subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/. |
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[The bug was that it was starting one character too far in when skipping |
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over the character class, thus treating the ] as data rather than |
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terminating the class. This meant it could skip too much.] |
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20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the |
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/g option in pcretest when the pattern contains \K, which makes it possible |
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to have an empty string match not at the start, even when the pattern is |
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anchored. Updated pcretest and pcredemo to use this option. |
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21. If the maximum number of capturing subpatterns in a recursion was greater |
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than the maximum at the outer level, the higher number was returned, but |
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with unset values at the outer level. The correct (outer level) value is |
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now given. |
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22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of |
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PCRE did not set those parentheses (unlike Perl). I have now found a way to |
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make it do so. The string so far is captured, making this feature |
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compatible with Perl. |
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23. The tests have been re-organized, adding tests 11 and 12, to make it |
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possible to check the Perl 5.10 features against Perl 5.10. |
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24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine |
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pattern matches a fixed length string. PCRE did not allow this; now it |
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does. Neither allows recursion. |
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25. I finally figured out how to implement a request to provide the minimum |
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length of subject string that was needed in order to match a given pattern. |
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(It was back references and recursion that I had previously got hung up |
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on.) This code has now been added to pcre_study(); it finds a lower bound |
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to the length of subject needed. It is not necessarily the greatest lower |
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bound, but using it to avoid searching strings that are too short does give |
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some useful speed-ups. The value is available to calling programs via |
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pcre_fullinfo(). |
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26. While implementing 25, I discovered to my embarrassment that pcretest had |
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not been passing the result of pcre_study() to pcre_dfa_exec(), so the |
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study optimizations had never been tested with that matching function. |
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Oops. What is worse, even when it was passed study data, there was a bug in |
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pcre_dfa_exec() that meant it never actually used it. Double oops. There |
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were also very few tests of studied patterns with pcre_dfa_exec(). |
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27. If (?| is used to create subpatterns with duplicate numbers, they are now |
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allowed to have the same name, even if PCRE_DUPNAMES is not set. However, |
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on the other side of the coin, they are no longer allowed to have different |
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names, because these cannot be distinguished in PCRE, and this has caused |
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confusion. (This is a difference from Perl.) |
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28. When duplicate subpattern names are present (necessarily with different |
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numbers, as required by 27 above), and a test is made by name in a |
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conditional pattern, either for a subpattern having been matched, or for |
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recursion in such a pattern, all the associated numbered subpatterns are |
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tested, and the overall condition is true if the condition is true for any |
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one of them. This is the way Perl works, and is also more like the way |
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testing by number works. |
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Version 7.9 11-Apr-09 |
Version 7.9 11-Apr-09 |
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--------------------- |
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