git: 8f7ed58a1555 - main - regex: mixed sets are misidentified as singletons
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Date: Fri, 22 Dec 2023 05:21:32 UTC
The branch main has been updated by yuripv: URL: https://cgit.FreeBSD.org/src/commit/?id=8f7ed58a15556bf567ff876e1999e4fe4d684e1d commit 8f7ed58a15556bf567ff876e1999e4fe4d684e1d Author: Bill Sommerfeld <sommerfeld@hamachi.org> AuthorDate: 2023-12-21 03:46:14 +0000 Commit: Yuri Pankov <yuripv@FreeBSD.org> CommitDate: 2023-12-22 05:19:59 +0000 regex: mixed sets are misidentified as singletons Fix "singleton" function used by regcomp() to turn character set matches into exact character matches if a character set has exactly one element. The underlying cset representation is complex; most critically it records"small" characters (codepoint less than either 128 or 256 depending on locale) in a bit vector, and "wide" characters in a secondary array. Unfortunately the "singleton" function uses to identify singleton sets treated a cset as a singleton if either the "small" or the "wide" sets had exactly one element (it would then ignore the other set). The easiest way to demonstrate this bug: $ export LANG=C.UTF-8 $ echo 'a' | grep '[abà]' It should match (and print "a") but instead it doesn't match because the single accented character in the set is misinterpreted as a singleton. Reviewed by: kevans, yuripv Obtained from: illumos Differential Revision: https://reviews.freebsd.org/D43149 --- lib/libc/regex/regcomp.c | 25 ++++++++++++++++++----- lib/libc/tests/regex/multibyte.sh | 43 ++++++++++++++++++++++++++++++++++++++- 2 files changed, 62 insertions(+), 6 deletions(-) diff --git a/lib/libc/regex/regcomp.c b/lib/libc/regex/regcomp.c index ba803130a050..89b96b00fefb 100644 --- a/lib/libc/regex/regcomp.c +++ b/lib/libc/regex/regcomp.c @@ -1586,17 +1586,32 @@ singleton(cset *cs) { wint_t i, s, n; + /* Exclude the complicated cases we don't want to deal with */ + if (cs->nranges != 0 || cs->ntypes != 0 || cs->icase != 0) + return (OUT); + + if (cs->nwides > 1) + return (OUT); + + /* Count the number of characters present in the bitmap */ for (i = n = 0; i < NC; i++) if (CHIN(cs, i)) { n++; s = i; } - if (n == 1) - return (s); - if (cs->nwides == 1 && cs->nranges == 0 && cs->ntypes == 0 && - cs->icase == 0) + + if (n > 1) + return (OUT); + + if (n == 1) { + if (cs->nwides == 0) + return (s); + else + return (OUT); + } + if (cs->nwides == 1) return (cs->wides[0]); - /* Don't bother handling the other cases. */ + return (OUT); } diff --git a/lib/libc/tests/regex/multibyte.sh b/lib/libc/tests/regex/multibyte.sh index a736352bf0a2..18323f500a2b 100755 --- a/lib/libc/tests/regex/multibyte.sh +++ b/lib/libc/tests/regex/multibyte.sh @@ -1,4 +1,3 @@ - atf_test_case bmpat bmpat_head() { @@ -45,8 +44,50 @@ icase_body() echo $c | atf_check -o "inline:$c\n" sed -ne "/$a/Ip" } +atf_test_case mbset cleanup +mbset_head() +{ + atf_set "descr" "Check multibyte sets matching" +} +mbset_body() +{ + export LC_CTYPE="C.UTF-8" + + # This involved an erroneously implemented optimization which reduces + # single-element sets to an exact match with a single codepoint. + # Match sets record small-codepoint characters in a bitmap and + # large-codepoint characters in an array; the optimization would falsely + # trigger if either the bitmap or the array was a singleton, ignoring + # the members of the other side of the set. + # + # To exercise this, we construct sets which have one member of one side + # and one or more of the other, and verify that all members can be + # found. + printf "a" > mbset; atf_check -o not-empty sed -ne '/[aà]/p' mbset + printf "à" > mbset; atf_check -o not-empty sed -ne '/[aà]/p' mbset + printf "a" > mbset; atf_check -o not-empty sed -ne '/[aàá]/p' mbset + printf "à" > mbset; atf_check -o not-empty sed -ne '/[aàá]/p' mbset + printf "á" > mbset; atf_check -o not-empty sed -ne '/[aàá]/p' mbset + printf "à" > mbset; atf_check -o not-empty sed -ne '/[abà]/p' mbset + printf "a" > mbset; atf_check -o not-empty sed -ne '/[abà]/p' mbset + printf "b" > mbset; atf_check -o not-empty sed -ne '/[abà]/p' mbset + printf "a" > mbset; atf_check -o not-empty sed -Ene '/[aà]/p' mbset + printf "à" > mbset; atf_check -o not-empty sed -Ene '/[aà]/p' mbset + printf "a" > mbset; atf_check -o not-empty sed -Ene '/[aàá]/p' mbset + printf "à" > mbset; atf_check -o not-empty sed -Ene '/[aàá]/p' mbset + printf "á" > mbset; atf_check -o not-empty sed -Ene '/[aàá]/p' mbset + printf "à" > mbset; atf_check -o not-empty sed -Ene '/[abà]/p' mbset + printf "a" > mbset; atf_check -o not-empty sed -Ene '/[abà]/p' mbset + printf "b" > mbset; atf_check -o not-empty sed -Ene '/[abà]/p' mbset +} +mbset_cleanup() +{ + rm -f mbset +} + atf_init_test_cases() { atf_add_test_case bmpat atf_add_test_case icase + atf_add_test_case mbset }