[PATCH v2 3/4] rename_ref: replace empty message in HEAD's log

[Kyle Meyer <kyle@kyleam.com>]

When the current branch is renamed, the deletion of the old ref is
recorded in HEAD's log with an empty message.  Now that delete_ref()
accepts a reflog message, provide a more descriptive message by
passing along the log message that is given to rename_ref().

The next step will be to extend HEAD's log to also include the second
part of the rename, the creation of the new branch.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Kyle Meyer <kyle@kyleam.com>
---
 refs/files-backend.c | 2 +-
 t/t3200-branch.sh    | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/refs/files-backend.c b/refs/files-backend.c
index 299eb4d8a..f6e7c192c 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -2616,7 +2616,7 @@ static int files_rename_ref(struct ref_store *ref_store,
 		return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
 			oldrefname, strerror(errno));
 
-	if (delete_ref(NULL, oldrefname, orig_sha1, REF_NODEREF)) {
+	if (delete_ref(logmsg, 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 8a833f354..0dbc54003 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -139,6 +139,11 @@ test_expect_success 'git branch -M baz bam should succeed when baz is checked ou
 	test $(git rev-parse --abbrev-ref HEAD) = bam
 '
 
+test_expect_success 'git branch -M baz bam should add entry to .git/logs/HEAD' '
+        msg="Branch: renamed refs/heads/baz to refs/heads/bam" &&
+	grep " 0\{40\}.*$msg$" .git/logs/HEAD
+'
+
 test_expect_success 'git branch -M baz bam should succeed when baz is checked out as linked working tree' '
 	git checkout master &&
 	git worktree add -b baz bazdir &&
-- 
2.11.1