1 files changed, 12 insertions, 2 deletions
diff --git a/sha1_name.c b/sha1_name.c
index c7c5ab376c..67961d6e47 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -1332,9 +1332,19 @@ void strbuf_branchname(struct strbuf *sb, const char *name, unsigned allowed)
 int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
 {
 	strbuf_branchname(sb, name, INTERPRET_BRANCH_LOCAL);
-	if (name[0] == '-')
-		return -1;
+
+	/*
+	 * This splice must be done even if we end up rejecting the
+	 * name; builtin/branch.c::copy_or_rename_branch() still wants
+	 * to see what the name expanded to so that "branch -m" can be
+	 * used as a tool to correct earlier mistakes.
+	 */
 	strbuf_splice(sb, 0, 0, "refs/heads/", 11);
+
+	if (*name == '-' ||
+	    !strcmp(sb->buf, "refs/heads/HEAD"))
+		return -1;
+
 	return check_refname_format(sb->buf, 0);
 }