am: reload .gitattributes after patching it

When applying multiple patches with git am, or when rebasing using the
am backend, it's possible that one of our patches has updated a
gitattributes file. Currently, we cache this information, so if a
file in a subsequent patch has attributes applied, the file will be
written out with the attributes in place as of the time we started the
rebase or am operation, not with the attributes applied by the previous
patch. This problem does not occur when using the -m or -i flags to
rebase.

To ensure we write the correct data into the working tree, expire the
cache after each patch that touches a path ending in ".gitattributes".
Since we load these attributes in multiple separate files, we must
expire them accordingly.

Verify that both the am and rebase code paths work correctly, including
the conflict marker size with am -3.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/t/t4150-am.sh b/t/t4150-am.sh
index 3f7f750..4f1e24e 100755
--- a/t/t4150-am.sh
+++ b/t/t4150-am.sh
@@ -1061,4 +1061,56 @@ test_expect_success 'am --quit keeps HEAD where it is' '
 	test_cmp expected actual
 '
 
+test_expect_success 'am and .gitattibutes' '
+	test_create_repo attributes &&
+	(
+		cd attributes &&
+		test_commit init &&
+		git config filter.test.clean "sed -e '\''s/smudged/clean/g'\''" &&
+		git config filter.test.smudge "sed -e '\''s/clean/smudged/g'\''" &&
+
+		test_commit second &&
+		git checkout -b test HEAD^ &&
+
+		echo "*.txt filter=test conflict-marker-size=10" >.gitattributes &&
+		git add .gitattributes &&
+		test_commit third &&
+
+		echo "This text is smudged." >a.txt &&
+		git add a.txt &&
+		test_commit fourth &&
+
+		git checkout -b removal HEAD^ &&
+		git rm .gitattributes &&
+		git add -u &&
+		test_commit fifth &&
+		git cherry-pick test &&
+
+		git checkout -b conflict third &&
+		echo "This text is different." >a.txt &&
+		git add a.txt &&
+		test_commit sixth &&
+
+		git checkout test &&
+		git format-patch --stdout master..HEAD >patches &&
+		git reset --hard master &&
+		git am patches &&
+		grep "smudged" a.txt &&
+
+		git checkout removal &&
+		git reset --hard &&
+		git format-patch --stdout master..HEAD >patches &&
+		git reset --hard master &&
+		git am patches &&
+		grep "clean" a.txt &&
+
+		git checkout conflict &&
+		git reset --hard &&
+		git format-patch --stdout master..HEAD >patches &&
+		git reset --hard fourth &&
+		test_must_fail git am -3 patches &&
+		grep "<<<<<<<<<<" a.txt
+	)
+'
+
 test_done