1 files changed, 40 insertions, 9 deletions

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 6ee962207c..825400dfd9 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -1108,9 +1108,28 @@ static int resolve_remote_submodule_branch(int argc, const char **argv,
 static int push_check(int argc, const char **argv, const char *prefix)
 {
 	struct remote *remote;
+	const char *superproject_head;
+	char *head;
+	int detached_head = 0;
+	struct object_id head_oid;
 
-	if (argc < 2)
-		die("submodule--helper push-check requires at least 1 argument");
+	if (argc < 3)
+		die("submodule--helper push-check requires at least 2 arguments");
+
+	/*
+	 * superproject's resolved head ref.
+	 * if HEAD then the superproject is in a detached head state, otherwise
+	 * it will be the resolved head ref.
+	 */
+	superproject_head = argv[1];
+	argv++;
+	argc--;
+	/* Get the submodule's head ref and determine if it is detached */
+	head = resolve_refdup("HEAD", 0, head_oid.hash, NULL);
+	if (!head)
+		die(_("Failed to resolve HEAD as a valid ref."));
+	if (!strcmp(head, "HEAD"))
+		detached_head = 1;
 
 	/*
 	 * The remote must be configured.
@@ -1133,18 +1152,30 @@ static int push_check(int argc, const char **argv, const char *prefix)
 			if (rs->pattern || rs->matching)
 				continue;
 
-			/*
-			 * LHS must match a single ref
-			 * NEEDSWORK: add logic to special case 'HEAD' once
-			 * working with submodules in a detached head state
-			 * ceases to be the norm.
-			 */
-			if (count_refspec_match(rs->src, local_refs, NULL) != 1)
+			/* LHS must match a single ref */
+			switch (count_refspec_match(rs->src, local_refs, NULL)) {
+			case 1:
+				break;
+			case 0:
+				/*
+				 * If LHS matches 'HEAD' then we need to ensure
+				 * that it matches the same named branch
+				 * checked out in the superproject.
+				 */
+				if (!strcmp(rs->src, "HEAD")) {
+					if (!detached_head &&
+					    !strcmp(head, superproject_head))
+						break;
+					die("HEAD does not match the named branch in the superproject");
+				}
+			default:
 				die("src refspec '%s' must name a ref",
 				    rs->src);
+			}
 		}
 		free_refspec(refspec_nr, refspec);
 	}
+	free(head);
 
 	return 0;
 }