[PATCH "FIX-RE2] match: fix re2 compability broken in 2e2699af5649

[Martin von Zweigbergk]

On Thu, Apr 11, 2019 at 9:55 AM Martin von Zweigbergk <martinvonz at google.com>
wrote:

>
>
> On Thu, Apr 11, 2019 at 9:53 AM Pierre-Yves David <
> pierre-yves.david at ens-lyon.org> wrote:
>
>>
>>
>> On 4/11/19 6:48 PM, Martin von Zweigbergk wrote:
>> >
>> >
>> > On Thu, Apr 11, 2019 at 9:46 AM Pierre-Yves David
>> > <pierre-yves.david at ens-lyon.org <mailto:pierre-yves.david at ens-lyon.org>>
>>
>> > wrote:
>> >
>> >     # HG changeset patch
>> >     # User Pierre-Yves David <pierre-yves.david at octobus.net
>> >     <mailto:pierre-yves.david at octobus.net>>
>> >     # Date 1555000496 -7200
>> >     #      Thu Apr 11 18:34:56 2019 +0200
>> >     # Node ID ca4f233c0f5c4ca5604a53c01216a16d136c69d8
>> >     # Parent  509a0477b3a6e9f1ea0fe32bfb028c256aada7fa
>> >     # EXP-Topic fix-2e2699af5649
>> >     # Available At https://bitbucket.org/octobus/mercurial-devel/
>> >     #              hg pull
>> >     https://bitbucket.org/octobus/mercurial-devel/ -r ca4f233c0f5c
>> >     match: fix re2 compability broken in 2e2699af5649
>> >
>> >     Apparently, the re2 regex matcher return False when no match are
>> found.
>> >
>> >
>> > This is not quite true; we explicitly use a different method on the
>> > compiled regex when we use re2:
>> >
>> https://www.mercurial-scm.org/repo/hg/file/509a0477b3a6/mercurial/match.py#l41
>>
>> The point is that the `_rematcher` call returns False instead of None,
>> breaking regex based matching.
>>
>
> Yes, I understand why it's broken. I just mean that "the re2 regex matcher
> return False when no match are found" is true, but it's misleading, because
> it makes it sounds like (to me, at least) like the re2 regex matcher
> behaves differently.
>

I'll change the message to the following in flight if you're okay with that.

When using re2, we call test_match() instead of match() on the

compiled regex object. While match() returns a matcher object or None,

test_match() returns True or False. So since 2e2699af5649 running test

on a machine with a re2 install fails in many places.  Instead we make

the code a bit more general and everything goes back to normal.



>
>>
>> >
>> >     So since
>> >     2e2699af5649 running test on a machine with a re2 install fails in
>> >     many places.
>> >     Instead we make the code a bit more general and everything goes back
>> >     to normal.
>> >
>> >     diff --git a/mercurial/match.py b/mercurial/match.py
>> >     --- a/mercurial/match.py
>> >     +++ b/mercurial/match.py
>> >     @@ -1288,7 +1288,7 @@ def _buildregexmatch(kindpats, globsuffi
>> >
>> >               if startidx == 0:
>> >                   matcher = _rematcher(fullregexp)
>> >     -            func = lambda s: matcher(s) is not None
>> >     +            func = lambda s: bool(matcher(s))
>> >               else:
>> >                   group = regexps[startidx:]
>> >                   allgroups.append(_joinregexes(group))
>> >
>>
>> --
>> Pierre-Yves David
>>
>
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