Sync with 2.30.3

* maint-2.30:
  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

compat/mingw.h

@@ -453,6 +453,13 @@ char *mingw_query_user_email(void);
 #include <inttypes.h>
 #endif
 
+/**
+ * Verifies that the specified path is owned by the user running the
+ * current process.
+ */
+int is_path_owned_by_current_sid(const char *path);
+#define is_path_owned_by_current_user is_path_owned_by_current_sid
+
 /**
  * Verifies that the given path is a valid one on Windows.
  *