[PATCH v2 04/12] t5520: test --rebase with multiple branches

Since rebasing on top of multiple upstream branches does not make sense,
since commit 51b2ead0 ("disallow providing multiple upstream branches
to rebase, pull --rebase"), git-pull explicitly disallowed specifying
multiple branches in the rebase case.

Implement tests to ensure that git-pull fails and prints out the
user-friendly error message in such a case.

Signed-off-by: Paul Tan <redacted>
---

Notes:
    * Check that when git-pull fails, HEAD was not moved.
    
    * Removed the not-really-required `test_when_finished "rm -f out"`.

 t/t5520-pull.sh | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/t/t5520-pull.sh b/t/t5520-pull.sh
index 99b6f67..05a92a2 100755
--- a/t/t5520-pull.sh
+++ b/t/t5520-pull.sh

@@ -220,6 +220,15 @@ test_expect_success '--rebase' '
 	test $(git rev-parse HEAD^) = $(git rev-parse copy) &&
 	test new = $(git show HEAD:file2)
 '
+
+test_expect_success '--rebase fails with multiple branches' '
+	git reset --hard before-rebase &&
+	test_must_fail git pull --rebase . copy master 2>out &&
+	test $(git rev-parse HEAD) = $(git rev-parse before-rebase) &&
+	test_i18ngrep "Cannot rebase onto multiple branches" out &&
+	test modified = "$(git show HEAD:file)"
+'
+
 test_expect_success 'pull.rebase' '
 	git reset --hard before-rebase &&
 	test_config pull.rebase true &&

-- 
2.1.4