[PATCH/RFC] add--interactive: ignore all internal submodule changes

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

For 'add -i' and 'add -p' the only action we can take on a dirty
submodule entry (from the superproject perspective) is its SHA-1. The
content changes inside do not matter, at least until interactive add has
--recurse-submodules or something.

Ignore all dirty changes to reduce the questions 'add -i' and 'add -p'
throw at the user when submodules are dirty.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 $DAYJOB started to use submodules and this annoys me so much when I
 use 'git add -p'. I'm neither very familiar with add--interactive nor
 submodules code but this seems to work. Hopefully it's a correct
 change.

 git-add--interactive.perl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/git-add--interactive.perl b/git-add--interactive.perl
index 28b325d754..964c3a7542 100755
--- a/git-add--interactive.perl
+++ b/git-add--interactive.perl
@@ -262,7 +262,7 @@ sub list_modified {
 		}
 	}
 
-	for (run_cmd_pipe(qw(git diff-files --numstat --summary --raw --), @ARGV)) {
+	for (run_cmd_pipe(qw(git diff-files --ignore-submodules=dirty --numstat --summary --raw --), @ARGV)) {
 		if (($add, $del, $file) =
 		    /^([-\d]+)	([-\d]+)	(.*)/) {
 			$file = unquote_path($file);
-- 
2.15.1.600.g899a5f85c6