Fix non-base64 data URIs passing text to BytesIO - #9394

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Thanks, the fix is right. A data URI without ;base64 should be URL-decoded to bytes (RFC 2397), and unquote_to_bytes does that. This error dates back to the python 2 to python 3 change.

One suggestion for the tests: GIF is loaded by Pillow or ffpyplayer, not the SDL3 loader, so these tests fail in an environment without Pillow. A PNG is always handled by SDL3, which keeps the test focused on the data URI decoding. For example:

png_path = os.path.join(kivy.kivy_data_dir, 'logo', 'kivy-icon-16.png')
with open(png_path, 'rb') as f:
    png = f.read()

CoreImage("data:image/png;base64," + b64encode(png).decode("ascii"))  # size (16, 16)
CoreImage("data:image/png," + quote_from_bytes(png))                  # size (16, 16)

I checked this on master: the percent-encoded PNG raises TypeError without your change and loads at 16x16 with it.

Thanks, switched the tests to the 16x16 PNG from kivy_data_dir in fa96f72, with one base64 and one percent-encoded load, both expecting (16, 16).

What I ran: on an older Kivy build without the fix, the base64 test passes and the percent-encoded one raises the TypeError, as you saw on master. I did not run it against this branch's code, so CI is the check there.

LGTM! Thank you.

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Successfully created backport PR for devel-2.3.x:

• [Backport devel-2.3.x] Fix non-base64 data URIs passing text to BytesIO #9510