t5520-pull: Test for rebased upstream + fetch + pull --rebase

If your upstream has rebased you can do:

git pull --rebase

but only if you haven't fetch before.

Mark this case as test_expect_failure, in a later patch it will be
changed to test_expect_success.

Signed-off-by: Santi Béjar <santi@agolina.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5520-pull.sh

@@ -117,6 +117,20 @@ test_expect_success '--rebase with rebased default upstream' '
 
 '
 
+test_expect_failure 'rebased upstream + fetch + pull --rebase' '
+
+	git update-ref refs/remotes/me/copy copy-orig &&
+	git reset --hard to-rebase-orig &&
+	git checkout --track -b to-rebase3 me/copy &&
+	git reset --hard to-rebase-orig &&
+	git fetch &&
+	test_must_fail git pull --rebase &&
+	git rebase --abort &&
+	test "conflicting modification" = "$(cat file)" &&
+	test file = "$(cat file2)"
+
+'
+
 test_expect_success 'pull --rebase dies early with dirty working directory' '
 
 	git checkout to-rebase &&