Commit Graph

9 Commits

Author SHA1 Message Date
Ævar Arnfjörð Bjarmason
870eea8166 grep: do not enter PCRE2_UTF mode on fixed matching
As discussed in the last commit partially fix a bug introduced in
b65abcafc7 ("grep: use PCRE v2 for optimized fixed-string search",
2019-07-01). Because PCRE v2, unlike kwset, validates its UTF-8 input
we'd die on e.g.:

    fatal: pcre2_match failed with error code -22: UTF-8 error:
    isolated byte with 0x80 bit set

When grepping a non-ASCII fixed string. This is a more general problem
that's hard to fix, but we can at least fix the most common case of
grepping for a fixed string without "-i". I can't think of a reason
for why we'd turn on PCRE2_UTF when matching byte-for-byte like that.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-07-26 13:56:40 -07:00
Ævar Arnfjörð Bjarmason
8a5999838e grep: stess test PCRE v2 on invalid UTF-8 data
Since my b65abcafc7 ("grep: use PCRE v2 for optimized fixed-string
search", 2019-07-01) we've been dying on invalid UTF-8 data when
grepping for fixed strings if the following are all true:

    * The subject string is non-ASCII (e.g. "ævar")
    * We're under a is_utf8_locale(), e.g. "en_US.UTF-8", not "C"
    * We compiled with PCRE v2
    * That PCRE v2 did not have JIT support

The last of those is why this wasn't caught earlier, per pcre2jit(3):

    "unless PCRE2_NO_UTF_CHECK is set, a UTF subject string is tested
    for validity. In the interests of speed, these checks do not
    happen on the JIT fast path, and if invalid data is passed, the
    result is undefined."

I.e. the subject being matched against our pattern was invalid, but we
were lucky and getting away with it on the JIT path, but the non-JIT
one is stricter.

This patch does nothing to fix that, instead we sneak in support for
fixed patterns starting with "(*NO_JIT)", this disables the PCRE v2
jit with implicit fixed-string matching for testing, see
pcre2syntax(3) the syntax.

This is technically a change in behavior, but it's so obscure that I
figured it was OK. We'd previously consider this an invalid regular
expression as regcomp() would die on it, now we feed it to the PCRE v2
fixed-string path. I thought this was better than introducing yet
another GIT_TEST_* environment variable.

We're also relying on a behavior of PCRE v2 that technically could
change, but I think the test coverage is worth dipping our toe into
some somewhat undefined behavior.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-07-26 13:56:40 -07:00
Nguyễn Thái Ngọc Duy
9038531f1b t/helper: merge test-regex into test-tool
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-27 08:45:47 -07:00
Ævar Arnfjörð Bjarmason
e01b4dab01 grep: change non-ASCII -i test to stop using --debug
Change a non-ASCII case-insensitive test case to stop using --debug,
and instead simply test for the expected results.

The test coverage remains the same with this change, but the test
won't break due to internal refactoring.

This test was added in commit 793dc676e0 ("grep/icase: avoid kwsset
when -F is specified", 2016-06-25). It was asserting that the regex
must be compiled with compile_fixed_regexp(), instead test for the
expected results, allowing the underlying implementation to change.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-21 08:25:37 +09:00
Ævar Arnfjörð Bjarmason
3eb585c112 test-lib: rename the LIBPCRE prerequisite to PCRE
Rename the LIBPCRE prerequisite to PCRE. This is for preparation for
libpcre2 support, where having just "LIBPCRE" would be confusing as it
implies v1 of the library.

None of these tests are incompatible between versions 1 & 2 of
libpcre, it's less confusing to give them a more general name to make
it clear that they work on both library versions.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-21 08:25:37 +09:00
Nguyễn Thái Ngọc Duy
b51a9c1479 diffcore-pickaxe: support case insensitive match on non-ascii
Similar to the "grep -F -i" case, we can't use kws on icase search
outside ascii range, so we quote the string and pass it to regcomp as
a basic regexp and let regex engine deal with case sensitivity.

The new test is put in t7812 instead of t4209-log-pickaxe because
lib-gettext.sh might cause problems elsewhere, probably.

Noticed-by: Plamen Totev <plamen.totev@abv.bg>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 12:44:57 -07:00
Nguyễn Thái Ngọc Duy
18547aacf5 grep/pcre: support utf-8
In the previous change in this function, we add locale support for
single-byte encodings only. It looks like pcre only supports utf-* as
multibyte encodings, the others are left in the cold (which is
fine).

We need to enable PCRE_UTF8 so pcre can find character boundary
correctly. It's needed for case folding (when --ignore-case is used)
or '*', '+' or similar syntax is used.

The "has_non_ascii()" check is to be on the conservative side. If
there's non-ascii in the pattern, the searched content could still be
in utf-8, but we can treat it just like a byte stream and everything
should work. If we force utf-8 based on locale only and pcre validates
utf-8 and the file content is in non-utf8 encoding, things break.

Noticed-by: Plamen Totev <plamen.totev@abv.bg>
Helped-by: Plamen Totev <plamen.totev@abv.bg>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 12:44:57 -07:00
Nguyễn Thái Ngọc Duy
793dc676e0 grep/icase: avoid kwsset when -F is specified
Similar to the previous commit, we can't use kws on icase search
outside ascii range. But we can't simply pass the pattern to
regcomp/pcre like the previous commit because it may contain regex
special characters, so we need to quote the regex first.

To avoid misquote traps that could lead to undefined behavior, we
always stick to basic regex engine in this case. We don't need fancy
features for grepping a literal string anyway.

basic_regex_quote_buf() assumes that if the pattern is in a multibyte
encoding, ascii chars must be unambiguously encoded as single
bytes. This is true at least for UTF-8. For others, let's wait until
people yell up. Chances are nobody uses multibyte, non utf-8 charsets
anymore.

Noticed-by: Plamen Totev <plamen.totev@abv.bg>
Helped-by: René Scharfe <l.s.r@web.de>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 12:44:30 -07:00
Nguyễn Thái Ngọc Duy
5c1ebcca4d grep/icase: avoid kwsset on literal non-ascii strings
When we detect the pattern is just a literal string, we avoid heavy
regex engine and use fast substring search implemented in kwsset.c.
But kws uses git-ctype which is locale-independent so it does not know
how to fold case properly outside ascii range. Let regcomp or pcre
take care of this case instead. Slower, but accurate.

Noticed-by: Plamen Totev <plamen.totev@abv.bg>
Helped-by: René Scharfe <l.s.r@web.de>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-06-27 07:31:35 -07:00