Ignore dirty submodule states during rebase and stash

When rebasing or stashing, chances are that you do not care about
dirty submodules, since they are not updated by those actions anyway.
So ignore the submodules' states.

Note: the submodule states -- as committed in the superproject --
will still be stashed and rebased, it is _just_ the state of the
submodule in the working tree which is ignored.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7402-submodule-rebase.sh

@@ -0,0 +1,92 @@
+#!/bin/sh
+#
+# Copyright (c) 2008 Johannes Schindelin
+#
+
+test_description='Test rebasing and stashing with dirty submodules'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+
+	echo file > file &&
+	git add file &&
+	test_tick &&
+	git commit -m initial &&
+	git clone . submodule &&
+	git add submodule &&
+	test_tick &&
+	git commit -m submodule &&
+	echo second line >> file &&
+	(cd submodule && git pull) &&
+	test_tick &&
+	git commit -m file-and-submodule -a
+
+'
+
+test_expect_success 'rebase with a dirty submodule' '
+
+	(cd submodule &&
+	 echo 3rd line >> file &&
+	 test_tick &&
+	 git commit -m fork -a) &&
+	echo unrelated >> file2 &&
+	git add file2 &&
+	test_tick &&
+	git commit -m unrelated file2 &&
+	echo other line >> file &&
+	test_tick &&
+	git commit -m update file &&
+	CURRENT=$(cd submodule && git rev-parse HEAD) &&
+	EXPECTED=$(git rev-parse HEAD~2:submodule) &&
+	GIT_TRACE=1 git rebase --onto HEAD~2 HEAD^ &&
+	STORED=$(git rev-parse HEAD:submodule) &&
+	test $EXPECTED = $STORED &&
+	test $CURRENT = $(cd submodule && git rev-parse HEAD)
+
+'
+
+cat > fake-editor.sh << \EOF
+#!/bin/sh
+echo $EDITOR_TEXT
+EOF
+chmod a+x fake-editor.sh
+
+test_expect_success 'interactive rebase with a dirty submodule' '
+
+	test submodule = $(git diff --name-only) &&
+	HEAD=$(git rev-parse HEAD) &&
+	GIT_EDITOR="\"$(pwd)/fake-editor.sh\"" EDITOR_TEXT="pick $HEAD" \
+		git rebase -i HEAD^ &&
+	test submodule = $(git diff --name-only)
+
+'
+
+test_expect_success 'rebase with dirty file and submodule fails' '
+
+	echo yet another line >> file &&
+	test_tick &&
+	git commit -m next file &&
+	echo rewrite > file &&
+	test_tick &&
+	git commit -m rewrite file &&
+	echo dirty > file &&
+	! git rebase --onto HEAD~2 HEAD^
+
+'
+
+test_expect_success 'stash with a dirty submodule' '
+
+	echo new > file &&
+	CURRENT=$(cd submodule && git rev-parse HEAD) &&
+	git stash &&
+	test new != $(cat file) &&
+	test submodule = $(git diff --name-only) &&
+	test $CURRENT = $(cd submodule && git rev-parse HEAD) &&
+	git stash apply &&
+	test new = $(cat file) &&
+	test $CURRENT = $(cd submodule && git rev-parse HEAD)
+
+'
+
+test_done