grep: fix colouring of matches with zero length

If a zero-length match is encountered, break out of loop and show the rest
of the line uncoloured.  Otherwise we'd be looping forever, trying to make
progress by advancing the pointer by zero characters.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/grep.c b/grep.c
index cc6d5b04c..7bf4a60ac 100644
--- a/grep.c
+++ b/grep.c
@@ -500,6 +500,8 @@ static void show_line(struct grep_opt *opt, char *bol, char *eol,
 
 		*eol = '\0';
 		while (next_match(opt, bol, eol, ctx, &match, eflags)) {
+			if (match.rm_so == match.rm_eo)
+				break;
 			printf("%.*s%s%.*s%s",
 			       (int)match.rm_so, bol,
 			       opt->color_match,