Factor the test for \0 in grep patterns into a function. Since commit 9eceddeec6 ("Use kwset in grep", 2011-08-21) any pattern containing a \0 is considered fixed as regcomp() can't handle it.
This limitation was never documented, and other some regular expression engines are capable of compiling a pattern containing a \0. Factoring this out makes a subsequent change which does that smaller. See a previous commit in this series ("grep: add tests to fix blind spots with \0 patterns", 2017-04-21) for further details & rationale. While I'm at it make the comment conform to the style guide, i.e. add an opening "/*\n". Signed-off-by: Ævar Arnfjörð Bjarmason <ava...@gmail.com> --- grep.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/grep.c b/grep.c index bf6c2494fd..79eb681c6e 100644 --- a/grep.c +++ b/grep.c @@ -321,6 +321,18 @@ static NORETURN void compile_regexp_failed(const struct grep_pat *p, die("%s'%s': %s", where, p->pattern, error); } +static int has_null(const char *s, size_t len) +{ + /* + * regcomp cannot accept patterns with NULs so when using it + * we consider any pattern containing a NUL fixed. + */ + if (memchr(s, 0, len)) + return 1; + + return 0; +} + #ifdef USE_LIBPCRE static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt) { @@ -394,12 +406,6 @@ static int is_fixed(const char *s, size_t len) { size_t i; - /* regcomp cannot accept patterns with NULs so we - * consider any pattern containing a NUL fixed. - */ - if (memchr(s, 0, len)) - return 1; - for (i = 0; i < len; i++) { if (is_regex_special(s[i])) return 0; @@ -451,7 +457,7 @@ static void compile_regexp(struct grep_pat *p, struct grep_opt *opt) * simple string match using kws. p->fixed tells us if we * want to use kws. */ - if (opt->fixed || is_fixed(p->pattern, p->patternlen)) + if (opt->fixed || has_null(p->pattern, p->patternlen) || is_fixed(p->pattern, p->patternlen)) p->fixed = !icase || ascii_only; else p->fixed = 0; -- 2.11.0