diff options
| -rw-r--r-- | ChangeLog | 9 | ||||
| -rw-r--r-- | re.c | 15 |
2 files changed, 21 insertions, 3 deletions
@@ -1,3 +1,12 @@ +2017-07-15 Arnold D. Robbins <arnold@skeeve.com> + + Revert change of 2016-07-24 that always runs the dfa + matcher. Based on a bug report from Alexandre Oliva + <lxoliva@fsfla.org>, DFA can cause gawk to hang, even + in the C locale. + + * re.c (research): Don't use dfa if need_start is true. + 2017-07-07 Arnold D. Robbins <arnold@skeeve.com> Remove warnings from GCC 7.1 compilation. @@ -268,17 +268,26 @@ research(Regexp *rp, char *str, int start, rp->pat.not_bol = 1; /* - * Always do dfa search if can; if it fails, we won't bother - * with the regex search. + * Always do dfa search if can; if it fails, then even if + * need_start is true, we won't bother with the regex search. * * The dfa matcher doesn't have a no_bol flag, so don't bother * trying it in that case. * + * 7/2008: Skip the dfa matcher if need_start. The dfa matcher + * has bugs in certain multibyte cases and it's too difficult + * to try to special case things. + * 7/2017: Apparently there are some cases where DFA gets + * stuck, even in the C locale, so we use dfa only if not need_start. + * + * Should that issue ever get resolved, note this comment: + * * 7/2016: The dfa matcher can't handle a case where searching * starts in the middle of a string, so don't bother trying it * in that case. + * if (rp->dfa && ! no_bol && start == 0) ... */ - if (rp->dfa && ! no_bol && start == 0) { + if (rp->dfa && ! no_bol && ! need_start) { char save; size_t count = 0; struct dfa *superset = dfasuperset(rp->dfareg); |