ImageTk.getimage is broken

[wiredfool]

What did you do?

Looked at the api, tried ImageTk.getimage

What did you expect to happen?

An Image.

What actually happened?

I got a TkError. Digging through the code, get image calls tkImaging.c:PyImagingPhotoGet:

static int
PyImagingPhotoGet(ClientData clientdata, Tcl_Interp* interp,
               int argc, char **argv)
{
    Tk_PhotoHandle photo;
    Tk_PhotoImageBlock block;

    if (argc != 2) {
        Tcl_AppendResult(interp, "usage: ", argv[0],
                         " srcPhoto", (char *) NULL);
        return TCL_ERROR;
    }

    /* get Tcl PhotoImage handle */
    photo = Tk_FindPhoto(interp, argv[1]);
    if (photo == NULL) {
        Tcl_AppendResult(
            interp, "source photo must exist", (char *) NULL
            );
        return TCL_ERROR;
    }

    Tk_PhotoGetImage(photo, &block);

    printf("pixelPtr = %p\n", block.pixelPtr);
    printf("width = %d\n", block.width);
    printf("height = %d\n", block.height);
    printf("pitch = %d\n", block.pitch);
    printf("pixelSize = %d\n", block.pixelSize);
    printf("offset = %d %d %d %d\n", block.offset[0], block.offset[1],
           block.offset[2], block.offset[3]);

    Tcl_AppendResult(
        interp, "this function is not yet supported", (char *) NULL
        );

    return TCL_ERROR;
}

Note that every code path ends in an error.

What versions of Pillow and Python are you using?

master. But it really doesn't matter, since most of this code hasn't been touched since the PIL import. Except for the Tk reorg. Which didn't actually check that this code could run.

This code is enough to see the error, added in viewer.py. Other repros are left as an exercise to the reader.

self.image = ImageTk.PhotoImage(im)
ImageTk.getimage(self.image)

[radarhere]

I've created PR #3814 to resolve this.