grep: ignore --recurse-submodules if --no-index is given

Since grep learned to recurse into submodules in 0281e487fd
(grep: optionally recurse into submodules, 2016-12-16),
using --recurse-submodules along with --no-index makes Git
die().

This is unfortunate because if submodule.recurse is set in a user's
~/.gitconfig, invoking `git grep --no-index` either inside or outside
a Git repository results in

    fatal: option not supported with --recurse-submodules

Let's allow using these options together, so that setting submodule.recurse
globally does not prevent using `git grep --no-index`.

Using `--recurse-submodules` should not have any effect if `--no-index`
is used inside a repository, as Git will recurse into the checked out
submodule directories just like into regular directories.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/t/t7814-grep-recurse-submodules.sh b/t/t7814-grep-recurse-submodules.sh
index 946f91f..828cb3b 100755
--- a/t/t7814-grep-recurse-submodules.sh
+++ b/t/t7814-grep-recurse-submodules.sh
@@ -345,7 +345,16 @@ test_incompatible_with_recurse_submodules ()
 }
 
 test_incompatible_with_recurse_submodules --untracked
-test_incompatible_with_recurse_submodules --no-index
+
+test_expect_success 'grep --recurse-submodules --no-index ignores --recurse-submodules' '
+	git grep --recurse-submodules --no-index -e "^(.|.)[\d]" >actual &&
+	cat >expect <<-\EOF &&
+	a:(1|2)d(3|4)
+	submodule/a:(1|2)d(3|4)
+	submodule/sub/a:(1|2)d(3|4)
+	EOF
+	test_cmp expect actual
+'
 
 test_expect_success 'grep --recurse-submodules should pass the pattern type along' '
 	# Fixed