gh-66410: Do not stringify arguments of Tkinter callback (GH-98592)

Callbacks registered in the tkinter module now take arguments as
various Python objects (int, float, bytes, tuple), not just str.
To restore the previous behavior set tkinter module global wantobject to 1
before creating the Tk object or call the wantobject() method of the Tk object
with argument 1.
Calling it with argument 2 restores the current default behavior.

Modules/_tkinter.c

@@ -2248,7 +2248,7 @@ _tkinter_tkapp_splitlist(TkappObject *self, PyObject *arg)
 
 /* Client data struct */
 typedef struct {
-    PyObject *self;
+    TkappObject *self;
     PyObject *func;
 } PythonCmd_ClientData;
 
@@ -2272,6 +2272,7 @@ PythonCmd(ClientData clientData, Tcl_Interp *interp,
     PyObject *args, *res;
     int i;
     Tcl_Obj *obj_res;
+    int objargs = data->self->wantobjects >= 2;
 
     ENTER_PYTHON
 
@@ -2280,7 +2281,8 @@ PythonCmd(ClientData clientData, Tcl_Interp *interp,
         return PythonCmd_Error(interp);
 
     for (i = 0; i < (objc - 1); i++) {
-        PyObject *s = unicodeFromTclObj(objv[i + 1]);
+        PyObject *s = objargs ? FromObj(data->self, objv[i + 1])
+                              : unicodeFromTclObj(objv[i + 1]);
         if (!s) {
             Py_DECREF(args);
             return PythonCmd_Error(interp);
@@ -2383,7 +2385,8 @@ _tkinter_tkapp_createcommand_impl(TkappObject *self, const char *name,
     data = PyMem_NEW(PythonCmd_ClientData, 1);
     if (!data)
         return PyErr_NoMemory();
-    data->self = Py_NewRef(self);
+    Py_INCREF(self);
+    data->self = self;
     data->func = Py_NewRef(func);
     if (self->threaded && self->thread_id != Tcl_GetCurrentThread()) {
         Tcl_Condition cond = NULL;
@@ -2897,10 +2900,10 @@ Tkapp_WantObjects(PyObject *self, PyObject *args)
 {
 
     int wantobjects = -1;
-    if (!PyArg_ParseTuple(args, "|p:wantobjects", &wantobjects))
+    if (!PyArg_ParseTuple(args, "|i:wantobjects", &wantobjects))
         return NULL;
     if (wantobjects == -1)
-        return PyBool_FromLong(((TkappObject*)self)->wantobjects);
+        return PyLong_FromLong(((TkappObject*)self)->wantobjects);
     ((TkappObject*)self)->wantobjects = wantobjects;
 
     Py_RETURN_NONE;
@@ -3086,7 +3089,7 @@ _tkinter.create
     baseName: str = ""
     className: str = "Tk"
     interactive: bool = False
-    wantobjects: bool = False
+    wantobjects: int = 0
     wantTk: bool = True
         if false, then Tk_Init() doesn't get called
     sync: bool = False
@@ -3102,7 +3105,7 @@ _tkinter_create_impl(PyObject *module, const char *screenName,
                      const char *baseName, const char *className,
                      int interactive, int wantobjects, int wantTk, int sync,
                      const char *use)
-/*[clinic end generated code: output=e3315607648e6bb4 input=09afef9adea70a19]*/
+/*[clinic end generated code: output=e3315607648e6bb4 input=7e382ba431bed537]*/
 {
     /* XXX baseName is not used anymore;
      * try getting rid of it. */