fix crash in regexec for nonzero nmatch argument with REG_NOSUB

per POSIX, the nmatch and pmatch arguments are ignored when the regex
was compiled with REG_NOSUB.

diff --git a/src/regex/regexec.c b/src/regex/regexec.c
index 855cef5..2e35b83 100644 (file)
--- a/src/regex/regexec.c
+++ b/src/regex/regexec.c
@@ -983,6 +983,7 @@ regexec(const regex_t *restrict preg, const char *restrict string,
   tre_tnfa_t *tnfa = (void *)preg->TRE_REGEX_T_FIELD;
   reg_errcode_t status;
   int *tags = NULL, eo;
+  if (tnfa->cflags & REG_NOSUB) nmatch = 0;
   if (tnfa->num_tags > 0 && nmatch > 0)
     {
       tags = xmalloc(sizeof(*tags) * tnfa->num_tags);