AssertionError in test_png

[opoplawski]

In Fedora Rawhide we are starting to see:

___________________________________ test_png ___________________________________
    def test_png():
        pixbuf_obj, format_name = pixbuf.decode_to_pixbuf(JPEG_BYTES)
        assert format_name == 'jpeg'
>       assert_decoded(pixbuf.pixbuf_to_cairo_slices(pixbuf_obj),
                       constants.FORMAT_RGB24, b'\xff\x00\x80\xff')
../BUILDROOT/usr/lib/python3.14/site-packages/cairocffi/test_pixbuf.py:67: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
pixbuf = <cairocffi.pixbuf.Pixbuf object at 0xffffaa772ea0>
    def pixbuf_to_cairo_slices(pixbuf):
        """Convert from PixBuf to ImageSurface, using slice-based byte swapping.
    
        This method is 2~5x slower than GDK but does not support an alpha channel.
        (cairo uses pre-multiplied alpha, but not Pixbuf.)
    
        """
        assert pixbuf.get_colorspace() == gdk_pixbuf.GDK_COLORSPACE_RGB
>       assert pixbuf.get_n_channels() == 3
E       AssertionError
../BUILDROOT/usr/lib/python3.14/site-packages/cairocffi/pixbuf.py:157: AssertionError

Looks like may have started with the update of gdk-pixbuf2 from 2.42.12-10.fc42 to 2.43.3-4.fc43, but could have been a number of other things, see https://koschei.fedoraproject.org/package/python-cairocffi?collection=f43

[liZe]

I suppose that it’s related to the new Glycin loader. What’s the value of pixbuf.get_n_channels()? The JPEG testing image really has 3 channels.

[liZe]

It’s a "bug" in the Glycin loader, fixed 2 weeks ago. I think that we can close this issue and wait for the next version if it’s OK for you.