grep: add --break

With --break, an empty line is printed between matches from different
files, increasing readability.  This option is taken from ack
(http://betterthangrep.com/).

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

1 files changed, 28 insertions, 0 deletions

diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index 539a8fe..f55793e 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh
@@ -746,4 +746,32 @@ test_expect_success 'grep --color, separator' '
 	test_cmp expected actual
 '
 
+cat >expected <<EOF
+hello.c:int main(int argc, const char **argv)
+hello.c:	/* char ?? */
+
+hello_world:Hello_world
+EOF
+
+test_expect_success 'grep --break' '
+	git grep --break -e char -e lo_w hello.c hello_world >actual &&
+	test_cmp expected actual
+'
+
+cat >expected <<EOF
+hello.c:int main(int argc, const char **argv)
+hello.c-{
+--
+hello.c:	/* char ?? */
+hello.c-}
+
+hello_world:Hello_world
+hello_world-HeLLo_world
+EOF
+
+test_expect_success 'grep --break with context' '
+	git grep --break -A1 -e char -e lo_w hello.c hello_world >actual &&
+	test_cmp expected actual
+'
+
 test_done