gh-125234: Make PyInitConfig_Free(NULL) a no-op (#125266)

Author: rruuaanng

Doc/c-api/init_config.rst

@@ -1621,6 +1621,8 @@ Create Config
 
    Free memory of the initialization configuration *config*.
 
+   If *config* is ``NULL``, no operation is performed.
+
 
 Error Handling
 --------------

Programs/_testembed.c

@@ -1896,6 +1896,7 @@ static int test_initconfig_api(void)
         goto error;
     }
     PyInitConfig_Free(config);
+    PyInitConfig_Free(NULL);
 
     dump_config();
     Py_Finalize();

Python/initconfig.c

@@ -3457,6 +3457,9 @@ PyInitConfig_Create(void)
 void
 PyInitConfig_Free(PyInitConfig *config)
 {
+    if (config == NULL) {
+        return;
+    }
     free(config->err_msg);
     free(config);
 }