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[PATCH v4 14/31] grep: add tests to fix blind spots with \0 patterns

From
Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Date
May 25, 2017, 19:45 UTC
Message-ID
<20170525194535.9324-15-avarab@gmail.com>
In-Reply-To
<20170525194535.9324-1-avarab@gmail.com>

Address a big blind spot in the tests for patterns containing \0. The is_fixed() function considers any string that contains \0 fixed, even if it contains regular expression metacharacters, those patterns are currently matched with kwset.

Before this change removing that memchr(s, 0, len) check from is_fixed() wouldn't change the result of any of the tests, since regcomp() will happily match the part before the \0.

The kwset path is dependent on whether the the -i flag is on, and whether the pattern has any non-ASCII characters, but none of this was tested for.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 t/t7008-grep-binary.sh | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)
diff --git a/t/t7008-grep-binary.sh b/t/t7008-grep-binary.sh
index 20370d6e0c..615e7e0162 100755
--- a/t/t7008-grep-binary.sh
+++ b/t/t7008-grep-binary.sh
@@ -22,6 +22,18 @@ nul_match () {
 			printf '$pattern' | q_to_nul >f &&
 			test_must_fail git grep -f f $flags a
 		"
+	elif test "$matches" = T1
+	then
+		test_expect_failure "git grep -f f $flags '$pattern_human' a" "
+			printf '$pattern' | q_to_nul >f &&
+			git grep -f f $flags a
+		"
+	elif test "$matches" = T0
+	then
+		test_expect_failure "git grep -f f $flags '$pattern_human' a" "
+			printf '$pattern' | q_to_nul >f &&
+			test_must_fail git grep -f f $flags a
+		"
 	else
 		test_expect_success "PANIC: Test framework error. Unknown matches value $matches" 'false'
 	fi
@@ -98,6 +110,65 @@ nul_match 1 '-Fi' 'YQf'
 nul_match 0 '-Fi' 'YQx'
 nul_match 1 '' 'yQf'
 nul_match 0 '' 'yQx'
+nul_match 1 '' 'æQð'
+nul_match 1 '-F' 'eQm[*]c'
+nul_match 1 '-Fi' 'EQM[*]C'
+
+# Regex patterns that would match but shouldn't with -F
+nul_match 0 '-F' 'yQ[f]'
+nul_match 0 '-F' '[y]Qf'
+nul_match 0 '-Fi' 'YQ[F]'
+nul_match 0 '-Fi' '[Y]QF'
+nul_match 0 '-F' 'æQ[ð]'
+nul_match 0 '-F' '[æ]Qð'
+nul_match 0 '-Fi' 'ÆQ[Ð]'
+nul_match 0 '-Fi' '[Æ]QÐ'
+
+# kwset is disabled on -i & non-ASCII. No way to match non-ASCII \0
+# patterns case-insensitively.
+nul_match T1 '-i' 'ÆQÐ'
+
+# \0 implicitly disables regexes. This is an undocumented internal
+# limitation.
+nul_match T1 '' 'yQ[f]'
+nul_match T1 '' '[y]Qf'
+nul_match T1 '-i' 'YQ[F]'
+nul_match T1 '-i' '[Y]Qf'
+nul_match T1 '' 'æQ[ð]'
+nul_match T1 '' '[æ]Qð'
+nul_match T1 '-i' 'ÆQ[Ð]'
+
+# ... because of \0 implicitly disabling regexes regexes that
+# should/shouldn't match don't do the right thing.
+nul_match T1 '' 'eQm.*cQ'
+nul_match T1 '-i' 'EQM.*cQ'
+nul_match T0 '' 'eQm[*]c'
+nul_match T0 '-i' 'EQM[*]C'
+
+# Due to the REG_STARTEND extension when kwset() is disabled on -i &
+# non-ASCII the string will be matched in its entirety, but the
+# pattern will be cut off at the first \0.
+nul_match 0 '-i' 'NOMATCHQð'
+nul_match T0 '-i' '[Æ]QNOMATCH'
+nul_match T0 '-i' '[æ]QNOMATCH'
+# Matches, but for the wrong reasons, just stops at [æ]
+nul_match 1 '-i' '[Æ]Qð'
+nul_match 1 '-i' '[æ]Qð'
+
+# Ensure that the matcher doesn't regress to something that stops at
+# \0
+nul_match 0 '-F' 'yQ[f]'
+nul_match 0 '-Fi' 'YQ[F]'
+nul_match 0 '' 'yQNOMATCH'
+nul_match 0 '' 'QNOMATCH'
+nul_match 0 '-i' 'YQNOMATCH'
+nul_match 0 '-i' 'QNOMATCH'
+nul_match 0 '-F' 'æQ[ð]'
+nul_match 0 '-Fi' 'ÆQ[Ð]'
+nul_match 0 '' 'yQNÓMATCH'
+nul_match 0 '' 'QNÓMATCH'
+nul_match 0 '-i' 'YQNÓMATCH'
+nul_match 0 '-i' 'QNÓMATCH'
 
 test_expect_success 'grep respects binary diff attribute' '
 	echo text >t &&

-- 
2.13.0.303.g4ebf302169
Previous: Ævar Arnfjörð BjarmasonNext: Ævar Arnfjörð Bjarmason
Message 15 of 32 in “Easy to review grep & pre-PCRE changes”
  1. 00/31 Easy to review grep & pre-PCRE changesÆvar Arnfjörð Bjarmason, May 25, 2017
  2. 01/31 Makefile & configure: reword inaccurate comment about PCREÆvar Arnfjörð Bjarmason, May 25, 2017
  3. 02/31 grep & rev-list doc: stop promising libpcre for --perl-regexpÆvar Arnfjörð Bjarmason, May 25, 2017
  4. 04/31 log: add exhaustive tests for pattern style options & configÆvar Arnfjörð Bjarmason, May 25, 2017
  5. 03/31 test-lib: rename the LIBPCRE prerequisite to PCREÆvar Arnfjörð Bjarmason, May 25, 2017
  6. 05/31 log: make --regexp-ignore-case work with --perl-regexpÆvar Arnfjörð Bjarmason, May 25, 2017
  7. 07/31 grep: add a test for backreferences in PCRE patternsÆvar Arnfjörð Bjarmason, May 25, 2017
  8. 08/31 grep: change non-ASCII -i test to stop using --debugÆvar Arnfjörð Bjarmason, May 25, 2017
  9. 06/31 grep: add a test asserting that --perl-regexp dies when !PCREÆvar Arnfjörð Bjarmason, May 25, 2017
  10. 09/31 grep: add tests for --threads=N and grep.threadsÆvar Arnfjörð Bjarmason, May 25, 2017
  11. 10/31 grep: amend submodule recursion test for regex engine testingÆvar Arnfjörð Bjarmason, May 25, 2017
  12. 11/31 grep: add tests for grep pattern types being passed to submodulesÆvar Arnfjörð Bjarmason, May 25, 2017
  13. 12/31 grep: add a test helper function for less verbose -f \0 testsÆvar Arnfjörð Bjarmason, May 25, 2017
  14. 13/31 grep: prepare for testing binary regexes containing rx metacharactersÆvar Arnfjörð Bjarmason, May 25, 2017
  15. 14/31 grep: add tests to fix blind spots with \0 patternsÆvar Arnfjörð Bjarmason, May 25, 2017
  16. 16/31 perf: emit progress output when unpacking & buildingÆvar Arnfjörð Bjarmason, May 25, 2017
  17. 18/31 perf: add a comparison test of grep regex engines with -FÆvar Arnfjörð Bjarmason, May 25, 2017
  18. 17/31 perf: add a comparison test of grep regex enginesÆvar Arnfjörð Bjarmason, May 25, 2017
  19. 15/31 perf: add a GIT_PERF_MAKE_COMMAND for when *_MAKE_OPTS won't doÆvar Arnfjörð Bjarmason, May 25, 2017
  20. 19/31 perf: add a comparison test of log --grep regex enginesÆvar Arnfjörð Bjarmason, May 25, 2017
  21. 20/31 perf: add a comparison test of log --grep regex engines with -FÆvar Arnfjörð Bjarmason, May 25, 2017
  22. 24/31 grep: change the internal PCRE macro names to be PCRE1Ævar Arnfjörð Bjarmason, May 25, 2017
  23. 23/31 grep: factor test for \0 in grep patterns into a functionÆvar Arnfjörð Bjarmason, May 25, 2017
  24. 21/31 grep: catch a missing enum in switch statementÆvar Arnfjörð Bjarmason, May 25, 2017
  25. 22/31 grep: remove redundant regflags assignmentsÆvar Arnfjörð Bjarmason, May 25, 2017
  26. 28/31 pack-objects & index-pack: add test for --threads warningÆvar Arnfjörð Bjarmason, May 25, 2017
  27. 30/31 grep: given --threads with NO_PTHREADS=YesPlease, warnÆvar Arnfjörð Bjarmason, May 25, 2017
  28. 25/31 grep: change internal *pcre* variable & function names to be *pcre1*Ævar Arnfjörð Bjarmason, May 25, 2017
  29. 31/31 grep: assert that threading is enabled when calling grep_{lock,unlock}Ævar Arnfjörð Bjarmason, May 25, 2017
  30. 29/31 pack-objects: fix buggy warning about threadsÆvar Arnfjörð Bjarmason, May 25, 2017
  31. 27/31 test-lib: add a PTHREADS prerequisiteÆvar Arnfjörð Bjarmason, May 25, 2017
  32. 26/31 grep: move is_fixed() earlier to avoid forward declarationÆvar Arnfjörð Bjarmason, May 25, 2017

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