grep -P: Fix matching ^ and $

When "git grep" is run with -P/--perl-regexp, it doesn't match ^ and $ at
the beginning/end of the line.  This is because PCRE normally matches ^
and $ at the beginning/end of the whole text, not for each line, and "git
grep" passes a large chunk of text (possibly containing many lines) to
pcre_exec() and then splits the text into lines.

This makes "git grep -P" behave differently from "git grep -E" and also
from "grep -P" and "pcregrep":

	$ cat file
	a
	 b
	$ git grep --no-index -P '^ ' file
	$ git grep --no-index -E '^ ' file
	file: b
	$ grep -c -P '^ ' file
	 b
	$ pcregrep -c '^ ' file
	 b

Reported-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Signed-off-by: Michał Kiedrowicz <michal.kiedrowicz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/grep.c b/grep.c
index b29d09c7f6a5a7f9621fb5287eb07e72ece7f484..9c5e1cd950c8d1d97290a047fb3780482f8eb8b7 100644 (file)
--- a/grep.c
+++ b/grep.c
@@ -79,7 +79,7 @@ static void compile_pcre_regexp(struct grep_pat *p, const struct grep_opt *opt)
 {
        const char *error;
        int erroffset;
-       int options = 0;
+       int options = PCRE_MULTILINE;
 
        if (opt->ignore_case)
                options |= PCRE_CASELESS;