bpo-36763: Add _PyPreConfig._config_init (GH-13481)

* _PyPreConfig_GetGlobalConfig() and  _PyCoreConfig_GetGlobalConfig()
  now do nothing if the configuration was not initialized with
  _PyPreConfig_InitCompatConfig() and _PyCoreConfig_InitCompatConfig()
* Remove utf8_mode=-2 special case: use utf8_mode=-1 instead.
* Fix _PyPreConfig_InitPythonConfig():

  * isolated = 0 instead of -1
  * use_environment = 1 instead of -1

* Rename _PyConfig_INIT to  _PyConfig_INIT_COMPAT
* Rename _PyPreConfig_Init() to _PyPreConfig_InitCompatConfig()
* Rename _PyCoreConfig_Init() to _PyCoreConfig_InitCompatConfig()
* PyInterpreterState_New() now uses _PyCoreConfig_InitPythonConfig()
  as default configuration, but it's very quickly overriden anyway.
* _freeze_importlib.c uses _PyCoreConfig_SetString() to set
  program_name.
* Cleanup preconfig_init_utf8_mode(): cmdline is always non-NULL.

1 files changed, 6 insertions, 3 deletions

diff --git a/Python/frozenmain.c b/Python/frozenmain.c
index a51fb58..c3af080 100644
--- a/Python/frozenmain.c
+++ b/Python/frozenmain.c
@@ -40,7 +40,11 @@ Py_FrozenMain(int argc, char **argv)
     }
 
     _PyCoreConfig config;
-    _PyCoreConfig_InitPythonConfig(&config);
+    err = _PyCoreConfig_InitPythonConfig(&config);
+    if (_PyInitError_Failed(err)) {
+        _PyCoreConfig_Clear(&config);
+        _Py_ExitInitError(err);
+    }
     config.pathconfig_warnings = 0;   /* Suppress errors from getpath.c */
 
     if ((p = Py_GETENV("PYTHONINSPECT")) && *p != '\0')
@@ -82,8 +86,7 @@ Py_FrozenMain(int argc, char **argv)
         Py_SetProgramName(argv_copy[0]);
 
     err = _Py_InitializeFromConfig(&config);
-    /* No need to call _PyCoreConfig_Clear() since we didn't allocate any
-       memory: program_name is a constant string. */
+    _PyCoreConfig_Clear(&config);
     if (_PyInitError_Failed(err)) {
         _Py_ExitInitError(err);
     }