bpo-36763: Fix _PyPreConfig_InitCompatConfig() utf8_mode by vstinner · Pull Request #13518 · python/cpython

the-knights-who-say-ni

* _PyPreConfig_InitCompatConfig() sets utf8_mode to 0.
* Change Py_UTF8Mode default value to 0.
* Fix _PyPreConfig_Copy(): copy also _config_init attrbibute.
* Fix _PyPreConfig_GetGlobalConfig(): use Py_UTF8Mode if it's greater
  than 0, even if utf8_mode >= 0.
* Add unit tests on environment variables using Python API.