bpo-32030: Add _PyMainInterpreterConfig_ReadEnv() (#4542)

Py_GetPath() and Py_Main() now call
_PyMainInterpreterConfig_ReadEnv() to share the same code to get
environment variables.

Changes:

* Add _PyMainInterpreterConfig_ReadEnv()
* Add _PyMainInterpreterConfig_Clear()
* Add _PyMem_RawWcsdup()
* _PyMainInterpreterConfig: rename pythonhome to home
* Rename _Py_ReadMainInterpreterConfig() to
  _PyMainInterpreterConfig_Read()
* Use _Py_INIT_USER_ERR(), instead of _Py_INIT_ERR(), for decoding
  errors: the user is able to fix the issue, it's not a bug in
  Python. Same change was made in _Py_INIT_NO_MEMORY().
* Remove _Py_GetPythonHomeWithConfig()

1 files changed, 18 insertions, 0 deletions

diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c
index 96a451ee49..9bd9798630 100644
--- a/Objects/obmalloc.c
+++ b/Objects/obmalloc.c
@@ -455,6 +455,24 @@ PyMem_Free(void *ptr)
 }
 
 
+wchar_t*
+_PyMem_RawWcsdup(const wchar_t *str)
+{
+    size_t len = wcslen(str);
+    if (len > (size_t)PY_SSIZE_T_MAX / sizeof(wchar_t) - 1) {
+        return NULL;
+    }
+
+    size_t size = (len + 1) * sizeof(wchar_t);
+    wchar_t *str2 = PyMem_RawMalloc(size);
+    if (str2 == NULL) {
+        return NULL;
+    }
+
+    memcpy(str2, str, size);
+    return str2;
+}
+
 char *
 _PyMem_RawStrdup(const char *str)
 {