Use PyCapsule in _imagingtk

src/PIL/ImageTk.py

@@ -48,18 +48,18 @@ def _get_image_from_kw(kw: dict[str, Any]) -> ImageFile.ImageFile | None:
 
 
 def _pyimagingtkcall(
-    command: str, photo: PhotoImage | tkinter.PhotoImage, id: int
+    command: str, photo: PhotoImage | tkinter.PhotoImage, ptr: object
 ) -> None:
     tk = photo.tk
     try:
-        tk.call(command, photo, id)
+        tk.call(command, photo, repr(ptr))
     except tkinter.TclError:
         # activate Tkinter hook
         # may raise an error if it cannot attach to Tkinter
         from . import _imagingtk
 
         _imagingtk.tkinit(tk.interpaddr())
-        tk.call(command, photo, id)
+        tk.call(command, photo, repr(ptr))
 
 
 # --------------------------------------------------------------------
@@ -181,7 +181,7 @@ class PhotoImage:
             block = image.new_block(self.__mode, im.size)
             image.convert2(block, image)  # convert directly between buffers
 
-        _pyimagingtkcall("PyImagingPhoto", self.__photo, block.id)
+        _pyimagingtkcall("PyImagingPhoto", self.__photo, block.ptr)
 
 
 # --------------------------------------------------------------------
@@ -255,9 +255,8 @@ class BitmapImage:
 def getimage(photo: PhotoImage) -> Image.Image:
     """Copies the contents of a PhotoImage to a PIL image memory."""
     im = Image.new("RGBA", (photo.width(), photo.height()))
-    block = im.im
 
-    _pyimagingtkcall("PyImagingPhotoGet", photo, block.id)
+    _pyimagingtkcall("PyImagingPhotoGet", photo, im.im.ptr)
 
     return im
 

src/Tk/tkImaging.c

@@ -56,19 +56,36 @@ static Tk_PhotoPutBlock_t TK_PHOTO_PUT_BLOCK;
 
 static Imaging
 ImagingFind(const char *name) {
-    Py_ssize_t id;
+    PyObject *capsule;
+    int direct_pointer = 0;
+    const char *expected = "capsule object \"" IMAGING_MAGIC "\" at 0x";
 
-    /* FIXME: use CObject instead? */
-#if defined(_WIN64)
-    id = _atoi64(name);
-#else
-    id = atol(name);
-#endif
-    if (!id) {
+    if (name[0] == '<') {
+        name++;
+    } else {
+        // Special case for PyPy, where the string representation of a Capsule
+        // refers directly to the pointer itself, not to the PyCapsule object.
+        direct_pointer = 1;
+    }
+
+    if (strncmp(name, expected, strlen(expected))) {
         return NULL;
     }
 
-    return (Imaging)id;
+    capsule = (PyObject *)strtoull(name + strlen(expected), NULL, 16);
+
+    if (direct_pointer) {
+        return (Imaging)capsule;
+    }
+
+    if (!PyCapsule_IsValid(capsule, IMAGING_MAGIC)) {
+        PyErr_Format(
+            PyExc_TypeError, "Expected PyCapsule with '%s' name.", IMAGING_MAGIC
+        );
+        return NULL;
+    }
+
+    return (Imaging)PyCapsule_GetPointer(capsule, IMAGING_MAGIC);
 }
 
 static int