update_walk: add "pure" attributes

src/update_walk.c

@@ -519,6 +519,7 @@ update_directory_child(struct directory *directory,
 }
 
 /* we don't look at "." / ".." nor files with newlines in their name */
+G_GNUC_PURE
 static bool skip_path(const char *path)
 {
 	return (path[0] == '.' && path[1] == 0) ||
@@ -526,6 +527,7 @@ static bool skip_path(const char *path)
 		strchr(path, '\n') != NULL;
 }
 
+G_GNUC_PURE
 static bool
 skip_symlink(const struct directory *directory, const char *utf8_name)
 {