gh-112358: Fix Python 3.12 regression with subclassing struct.Struct. (#112424)

Revert commit c8c0afc7137ab9f22bf59d591084948ca967c97c (PR #94532),
which moved `struct.Struct` initialisation from `Struct.__init__` to `Struct.__new__`.
This caused issues with code in the wild that subclasses `struct.Struct`.

1 files changed, 8 insertions, 8 deletions

diff --git a/Modules/clinic/_struct.c.h b/Modules/clinic/_struct.c.h
index e5118fb..1a07532 100644
--- a/Modules/clinic/_struct.c.h
+++ b/Modules/clinic/_struct.c.h
@@ -9,7 +9,7 @@ preserve
 #include "pycore_abstract.h"      // _PyNumber_Index()
 #include "pycore_modsupport.h"    // _PyArg_UnpackKeywords()
 
-PyDoc_STRVAR(Struct__doc__,
+PyDoc_STRVAR(Struct___init____doc__,
 "Struct(format)\n"
 "--\n"
 "\n"
@@ -20,13 +20,13 @@ PyDoc_STRVAR(Struct__doc__,
 "\n"
 "See help(struct) for more on format strings.");
 
-static PyObject *
-Struct_impl(PyTypeObject *type, PyObject *format);
+static int
+Struct___init___impl(PyStructObject *self, PyObject *format);
 
-static PyObject *
-Struct(PyTypeObject *type, PyObject *args, PyObject *kwargs)
+static int
+Struct___init__(PyObject *self, PyObject *args, PyObject *kwargs)
 {
-    PyObject *return_value = NULL;
+    int return_value = -1;
     #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
 
     #define NUM_KEYWORDS 1
@@ -62,7 +62,7 @@ Struct(PyTypeObject *type, PyObject *args, PyObject *kwargs)
         goto exit;
     }
     format = fastargs[0];
-    return_value = Struct_impl(type, format);
+    return_value = Struct___init___impl((PyStructObject *)self, format);
 
 exit:
     return return_value;
@@ -436,4 +436,4 @@ exit:
 
     return return_value;
 }
-/*[clinic end generated code: output=6a20e87f9b298b14 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=67bd299e5d72fee0 input=a9049054013a1b77]*/