[PATCH v6 19/32] refs: don't dereference on rename

@@ -2372,7 +2372,7 @@ static int files_rename_ref(const char *oldrefname, const char *newrefname,
 			    const char *logmsg)
 {
 	unsigned char sha1[20], orig_sha1[20];
-	int flag = 0, logmoved = 0;
+	int flag = 0, logmoved = 0, resolve_flags;
 	struct ref_lock *lock;
 	struct stat loginfo;
 	int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);

@@ -2382,7 +2382,8 @@ static int files_rename_ref(const char *oldrefname, const char *newrefname,
 	if (log && S_ISLNK(loginfo.st_mode))
 		return error("reflog for %s is a symlink", oldrefname);
 
-	symref = resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING,
+	resolve_flags = RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE;
+	symref = resolve_ref_unsafe(oldrefname, resolve_flags,
 				    orig_sha1, &flag);
 	if (flag & REF_ISSYMREF)
 		return error("refname %s is a symbolic ref, renaming it is not supported",

@@ -2402,8 +2403,8 @@ static int files_rename_ref(const char *oldrefname, const char *newrefname,
 		goto rollback;
 	}
 
-	if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&
-	    delete_ref(newrefname, sha1, REF_NODEREF)) {
+	if (!read_ref_full(newrefname, resolve_flags, sha1, NULL) &&
+	    delete_ref(newrefname, NULL, REF_NODEREF)) {
 		if (errno==EISDIR) {
 			struct strbuf path = STRBUF_INIT;
 			int result;

@@ -2427,7 +2428,8 @@ static int files_rename_ref(const char *oldrefname, const char *newrefname,
 
 	logmoved = log;
 
-	lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, 0, NULL, &err);
+	lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, REF_NODEREF,
+				   NULL, &err);
 	if (!lock) {
 		error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf);
 		strbuf_release(&err);

@@ -2445,7 +2447,8 @@ static int files_rename_ref(const char *oldrefname, const char *newrefname,
 	return 0;
 
  rollback:
-	lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, 0, NULL, &err);
+	lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, REF_NODEREF,
+				   NULL, &err);
 	if (!lock) {
 		error("unable to lock %s for rollback: %s", oldrefname, err.buf);
 		strbuf_release(&err);

@@ -79,6 +79,15 @@ test_expect_success 'git branch -m dumps usage' '
 	test_i18ngrep "branch name required" err
 '
 
+test_expect_success 'git branch -m m broken_symref should work' '
+	test_when_finished "git branch -D broken_symref" &&
+	git branch -l m &&
+	git symbolic-ref refs/heads/broken_symref refs/heads/i_am_broken &&
+	git branch -m m broken_symref &&
+	git reflog exists refs/heads/broken_symref &&
+	test_must_fail git reflog exists refs/heads/i_am_broken
+'
+
 test_expect_success 'git branch -m m m/m should work' '
 	git branch -l m &&
 	git branch -m m m/m &&