[PATCH v3 5/9] t5520: test work tree fast-forward when fetch updates head

[Paul Tan <pyokagan@gmail.com>]

Since b10ac50 (Fix pulling into the same branch., 2005-08-25), git-pull,
upon detecting that git-fetch updated the current head, will
fast-forward the working tree to the updated head commit.

Implement tests to ensure that the fast-forward occurs in such a case,
as well as to ensure that the user-friendly advice is printed upon
failure.

Signed-off-by: Paul Tan <pyokagan@gmail.com>
---

* Added git rev-parse checks to make it explicit that the branch head has
  been updated.

* "git checkout -b third second^" to make it explicit we are fast-forwarding.

 t/t5520-pull.sh | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/t/t5520-pull.sh b/t/t5520-pull.sh
index 8e95402..954e581 100755
--- a/t/t5520-pull.sh
+++ b/t/t5520-pull.sh
@@ -184,6 +184,27 @@ test_expect_success 'fail if the index has unresolved entries' '
 	test_cmp expected file
 '
 
+test_expect_success 'fast-forwards working tree if branch head is updated' '
+	git checkout -b third second^ &&
+	test_when_finished "git checkout -f copy && git branch -D third" &&
+	verbose test "$(cat file)" = file &&
+	git pull . second:third 2>err &&
+	test_i18ngrep "fetch updated the current branch head" err &&
+	verbose test "$(cat file)" = modified &&
+	verbose test "$(git rev-parse third)" = "$(git rev-parse second)"
+'
+
+test_expect_success 'fast-forward fails with conflicting work tree' '
+	git checkout -b third second^ &&
+	test_when_finished "git checkout -f copy && git branch -D third" &&
+	verbose test "$(cat file)" = file &&
+	echo conflict >file &&
+	test_must_fail git pull . second:third 2>err &&
+	test_i18ngrep "Cannot fast-forward your working tree" err &&
+	verbose test "$(cat file)" = conflict &&
+	verbose test "$(git rev-parse third)" = "$(git rev-parse second)"
+'
+
 test_expect_success '--rebase' '
 	git branch to-rebase &&
 	echo modified again > file &&
-- 
2.1.4