[PATCH v2] add--interactive: ignore submodule changes except HEAD

[Nguyễn Thái Ngọc Duy]

For 'add -i' and 'add -p', the only action we can take on a dirty
submodule entry is update the index with a new value from its HEAD. The
content changes inside (from its own index, untracked files...) do not
matter, at least until 'git add -i' learns about launching a new
interactive add session inside a submodule.

Ignore all other submodules changes except HEAD. This reduces the number
of entries the user has to check through in 'git add -i', and the number
of 'no' they have to answer to 'git add -p' when dirty submodules are
present.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclo...@gmail.com>
---
 v2 now has some tests. The commit message is rephrased a bit.

 git-add--interactive.perl  |  2 +-
 t/t3701-add-interactive.sh | 48 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 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);
diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
index a49c12c79b..058698df6a 100755
--- a/t/t3701-add-interactive.sh
+++ b/t/t3701-add-interactive.sh
@@ -493,4 +493,52 @@ test_expect_success 'add -p works even with 
color.ui=always' '
        test_cmp expect actual
 '
 
+test_expect_success 'setup different kinds of dirty submodules' '
+       test_create_repo for-submodules &&
+       (
+               cd for-submodules &&
+               test_commit initial &&
+               test_create_repo dirty-head &&
+               (
+                       cd dirty-head &&
+                       test_commit initial
+               ) &&
+               cp -R dirty-head dirty-otherwise &&
+               cp -R dirty-head dirty-both-ways &&
+               git add dirty-head &&
+               git add dirty-otherwise dirty-both-ways &&
+               git commit -m initial &&
+
+               cd dirty-head &&
+               test_commit updated &&
+               cd ../dirty-both-ways &&
+               test_commit updated &&
+               echo dirty >>initial &&
+               : >untracked &&
+               cd ../dirty-otherwise &&
+               echo dirty >>initial &&
+               : >untracked
+       ) &&
+       git -C for-submodules diff-files --name-only >actual &&
+       cat >expected <<-\EOF &&
+       dirty-both-ways
+       dirty-head
+       dirty-otherwise
+       EOF
+       test_cmp expected actual &&
+       git -C for-submodules diff-files --name-only --ignore-submodules=dirty 
>actual &&
+       cat >expected <<-\EOF &&
+       dirty-both-ways
+       dirty-head
+       EOF
+       test_cmp expected actual
+'
+
+test_expect_success 'status ignores dirty submodules (except HEAD)' '
+       git -C for-submodules add -i </dev/null >output &&
+       grep dirty-head output &&
+       grep dirty-both-ways output &&
+       ! grep dirty-otherwise output
+'
+
 test_done
-- 
2.15.1.600.g899a5f85c6