Sync with 2.31.2

* maint-2.31:
  Git 2.31.2
  Git 2.30.3
  setup_git_directory(): add an owner check for the top-level directory
  Add a function to determine whether a path is owned by the current user

path.c

@@ -1218,11 +1218,15 @@ int longest_ancestor_length(const char *path, struct string_list *prefixes)
 		const char *ceil = prefixes->items[i].string;
 		int len = strlen(ceil);
 
-		if (len == 1 && ceil[0] == '/')
-			len = 0; /* root matches anything, with length 0 */
-		else if (!strncmp(path, ceil, len) && path[len] == '/')
-			; /* match of length len */
-		else
+		/*
+		 * For root directories (`/`, `C:/`, `//server/share/`)
+		 * adjust the length to exclude the trailing slash.
+		 */
+		if (len > 0 && ceil[len - 1] == '/')
+			len--;
+
+		if (strncmp(path, ceil, len) ||
+		    path[len] != '/' || !path[len + 1])
 			continue; /* no match */
 
 		if (len > max_len)