pull --rebase: exit early when the working directory is dirty

When rebasing fails during "pull --rebase", you cannot just clean up the
working directory and call "pull --rebase" again, since the remote branch
was already fetched.

Therefore, die early when the working directory is dirty.

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

git-pull.sh

@@ -107,6 +107,11 @@ error_on_no_merge_candidates () {
 }
 
 test true = "$rebase" && {
+	git update-index --refresh &&
+	git diff-files --quiet &&
+	git diff-index --cached --quiet HEAD -- ||
+	die "refusing to pull with rebase: your working tree is not up-to-date"
+
 	. git-parse-remote &&
 	origin="$1"
 	test -z "$origin" && origin=$(get_default_remote)

t/t5520-pull.sh

@@ -92,4 +92,22 @@ test_expect_success '--rebase with rebased upstream' '
 
 '
 
+test_expect_success 'pull --rebase dies early with dirty working directory' '
+
+	git update-ref refs/remotes/me/copy copy^ &&
+	COPY=$(git rev-parse --verify me/copy) &&
+	git rebase --onto $COPY copy &&
+	git config branch.to-rebase.remote me &&
+	git config branch.to-rebase.merge refs/heads/copy &&
+	git config branch.to-rebase.rebase true &&
+	echo dirty >> file &&
+	git add file &&
+	test_must_fail git pull &&
+	test $COPY = $(git rev-parse --verify me/copy) &&
+	git checkout HEAD -- file &&
+	git pull &&
+	test $COPY != $(git rev-parse --verify me/copy)
+
+'
+
 test_done