[PATCH v11 35/41] refs.c: pack all refs before we start to rename a ref

[Ronnie Sahlberg <sahlberg@google.com>]

This means that most loose refs will no longer be present after the rename
which triggered a test failure since it assumes the file for an unrelated
ref would still be present after the rename.

We want to do this to make it easier to handle atomic renames in rename_ref for
the case 'git branch -m foo/bar foo'. If we can guarantee that foo/bar does not
exist as a loose ref we can avoid locking foo/bar.lock during transaction
commit and thus make it possible to delete the foo directory and re-create
it as a file(branch) in a single transaction.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
---
 refs.c            | 3 +++
 t/t3200-branch.sh | 6 +++---
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/refs.c b/refs.c
index 3cdfc72..08dde5b 100644
--- a/refs.c
+++ b/refs.c
@@ -2637,6 +2637,9 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms
 		return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
 			oldrefname, strerror(errno));
 
+	if (pack_refs(PACK_REFS_ALL | PACK_REFS_PRUNE))
+		return error("unable to pack refs");
+
 	if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
 		error("unable to delete old %s", oldrefname);
 		goto rollback;
diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index ac31b71..de0c2b9 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -288,9 +288,9 @@ test_expect_success 'deleting a dangling symref' '
 test_expect_success 'renaming a symref is not allowed' '
 	git symbolic-ref refs/heads/master2 refs/heads/master &&
 	test_must_fail git branch -m master2 master3 &&
-	git symbolic-ref refs/heads/master2 &&
-	test_path_is_file .git/refs/heads/master &&
-	test_path_is_missing .git/refs/heads/master3
+	git rev-parse --verify refs/heads/master &&
+	test_must_fail git symbolic-ref refs/heads/master3 &&
+	test_must_fail git rev-parse refs/heads/master3
 '
 
 test_expect_success SYMLINKS 'git branch -m u v should fail when the reflog for u is a symlink' '
-- 
2.0.0.rc3.474.g0203784