gh-99275: [ctypes] remove _use_broken_old_ctypes_structure_semantics_

Author: sobolevn

Include/internal/pycore_global_strings.h

@@ -250,7 +250,6 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(_swappedbytes_)
         STRUCT_FOR_ID(_type_)
         STRUCT_FOR_ID(_uninitialized_submodules)
-        STRUCT_FOR_ID(_use_broken_old_ctypes_structure_semantics_)
         STRUCT_FOR_ID(_warn_unawaited_coroutine)
         STRUCT_FOR_ID(_xoptions)
         STRUCT_FOR_ID(a)

Include/internal/pycore_runtime_init_generated.h

@@ -0,0 +1,2 @@
+Remove `_use_broken_old_ctypes_structure_semantics_` hack from
+:mod:`ctypes`.

Misc/NEWS.d/next/Library/2022-11-09-12-36-12.gh-issue-99284.9p4J2l.rst

@@ -357,14 +357,6 @@ PyCStructUnionType_update_stgdict(PyObject *type, PyObject *fields, int isStruct
     int big_endian;
     int arrays_seen = 0;
 
-    /* HACK Alert: I cannot be bothered to fix ctypes.com, so there has to
-       be a way to use the old, broken semantics: _fields_ are not extended
-       but replaced in subclasses.
-
-       XXX Remove this in ctypes 1.0!
-    */
-    int use_broken_old_ctypes_semantics;
-
     if (fields == NULL)
         return 0;
 
@@ -379,19 +371,6 @@ PyCStructUnionType_update_stgdict(PyObject *type, PyObject *fields, int isStruct
         big_endian = PY_BIG_ENDIAN;
     }
 
-    if (_PyObject_LookupAttr(type,
-                &_Py_ID(_use_broken_old_ctypes_structure_semantics_), &tmp) < 0)
-    {
-        return -1;
-    }
-    if (tmp) {
-        Py_DECREF(tmp);
-        use_broken_old_ctypes_semantics = 1;
-    }
-    else {
-        use_broken_old_ctypes_semantics = 0;
-    }
-
     if (_PyObject_LookupAttr(type, &_Py_ID(_pack_), &tmp) < 0) {
         return -1;
     }
@@ -455,7 +434,7 @@ PyCStructUnionType_update_stgdict(PyObject *type, PyObject *fields, int isStruct
     if (!isStruct) {
         stgdict->flags |= TYPEFLAG_HASUNION;
     }
-    if (basedict && !use_broken_old_ctypes_semantics) {
+    if (basedict) {
         size = offset = basedict->size;
         align = basedict->align;
         union_size = 0;

Modules/_ctypes/stgdict.c

@@ -758,7 +758,6 @@ Modules/_ctypes/callproc.c	unpickle	PyId___setstate__	-
 Modules/_ctypes/stgdict.c	MakeAnonFields	PyId__anonymous_	-
 Modules/_ctypes/stgdict.c	PyCStructUnionType_update_stgdict	PyId__pack_	-
 Modules/_ctypes/stgdict.c	PyCStructUnionType_update_stgdict	PyId__swappedbytes_	-
-Modules/_ctypes/stgdict.c	PyCStructUnionType_update_stgdict	PyId__use_broken_old_ctypes_structure_semantics_	-
 Modules/_cursesmodule.c	_curses_getwin	PyId_read	-
 Modules/_cursesmodule.c	_curses_window_putwin	PyId_write	-
 Modules/_cursesmodule.c	update_lines_cols	PyId_COLS	-