This patch works around some of the performance problems of multibyte grep.
The patch has been in RHEL-6 for a few months. I think it is also a
correctness patch, since grep has no way to support multi-character
collation elements.
For UTF-8 it should trigger only in the presence of MBCSET, e.g. [a-z].
For other character sets all brackets and `.` as well will trigger it.
* src/dfa.c (dfaexec): Fall back to glibc for multibyte matches,
if possible.
---
src/dfa.c | 9 +++++++++
1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/src/dfa.c b/src/dfa.c
index 91124b6..3708be7 100644
--- a/src/dfa.c
+++ b/src/dfa.c
@@ -3237,6 +3237,15 @@ dfaexec (struct dfa *d, char const *begin, char *end,
continue;
}
+ if (backref)
+ {
+ *backref = 1;
+ free(mblen_buf);
+ free(inputwcs);
+ *end = saved_end;
+ return (char *) p;
+ }
+
/* Can match with a multibyte character (and multi character
collating element). Transition table might be updated. */
s = transit_state(d, s, &p);
--
1.7.1
