ValueError: bad transparency mask with FrameAware wrapper

[mihalikv]

With latest version of easy-thumbnails 2.10 there is introduced support for gif processing.
I tried functionality with GIF attached in this issue, this gif have first frame with im.mode == 'P'. There is code here to convert every frame to 'RGBA' with help of FrameAware wraper, hover it is not working.
Currentlly I am not sure why, but here is test case how it should work and second test case with FrameAware where it is not working.

from PIL import Image
from easy_thumbnails.processors import FrameAware

def test_original_pil(im):
    num_frames = im.n_frames
    for i in range(num_frames):
        im.seek(i)
        print(im.mode)
        converted_image = im.convert('RGBA')
        base = Image.new('RGBA', converted_image.size, '#fff')
        base.paste(converted_image, mask=converted_image)

def test_with_frame_aware(im):
    num_frames = im.n_frames
    for i in range(num_frames):
        im.seek(i)
        im = FrameAware(im).convert('RGBA')
        base = Image.new('RGBA', im.size, '#fff')
        # this will fail with ValueError: bad transparency mask
        # on first frame with mode == 'P'
        base.paste(im, mask=im)

test_image = '/home/vilo/dog-smile.gif'
image_test_1 = Image.open(test_image)
test_original_pil(image_test_1)
image_test_2 = Image.open(test_image)
test_with_frame_aware(image_test_2)

[dkoenigroer]

Does this issue produce errors like this?

KeyError: 'P'
  File "PIL/JpegImagePlugin.py", line 639, in _save
    rawmode = RAWMODE[im.mode]
OSError: cannot write mode P as JPEG
  File "django/core/handlers/exception.py", line 55, in inner
    response = get_response(request)
  File "django/core/handlers/base.py", line 220, in _get_response
    response = response.render()
  File "django/template/response.py", line 114, in render
    self.content = self.rendered_content
  File "django/template/response.py", line 92, in rendered_content
    return template.render(context, self._request)
  File "django/template/backends/django.py", line 61, in render
    return self.template.render(context)
  File "django/template/base.py", line 171, in render
    return self._render(context)
  File "django/template/base.py", line 163, in _render
    return self.nodelist.render(context)
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/loader_tags.py", line 159, in render
    return compiled_parent._render(context)
  File "django/template/base.py", line 163, in _render
    return self.nodelist.render(context)
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/loader_tags.py", line 159, in render
    return compiled_parent._render(context)
  File "django/template/base.py", line 163, in _render
    return self.nodelist.render(context)
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/loader_tags.py", line 159, in render
    return compiled_parent._render(context)
  File "django/template/base.py", line 163, in _render
    return self.nodelist.render(context)
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/loader_tags.py", line 159, in render
    return compiled_parent._render(context)
  File "django/template/base.py", line 163, in _render
    return self.nodelist.render(context)
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/loader_tags.py", line 159, in render
    return compiled_parent._render(context)
  File "django/template/base.py", line 163, in _render
    return self.nodelist.render(context)
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/loader_tags.py", line 159, in render
    return compiled_parent._render(context)
  File "django/template/base.py", line 163, in _render
    return self.nodelist.render(context)
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/loader_tags.py", line 65, in render
    result = block.nodelist.render(context)
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/loader_tags.py", line 65, in render
    result = block.nodelist.render(context)
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/defaulttags.py", line 242, in render
    nodelist.append(node.render_annotated(context))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/loader_tags.py", line 210, in render
    return template.render(context)
  File "django/template/base.py", line 173, in render
    return self._render(context)
  File "django/template/base.py", line 163, in _render
    return self.nodelist.render(context)
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/defaulttags.py", line 242, in render
    nodelist.append(node.render_annotated(context))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/defaulttags.py", line 242, in render
    nodelist.append(node.render_annotated(context))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/defaulttags.py", line 326, in render
    return nodelist.render(context)
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/defaulttags.py", line 326, in render
    return nodelist.render(context)
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/base.py", line 1065, in render
    return render_value_in_context(output, context)
  File "django/template/base.py", line 1042, in render_value_in_context
    value = str(value)
  File "django/forms/utils.py", line 79, in __str__
    return self.as_widget()
  File "django/forms/boundfield.py", line 108, in as_widget
    return widget.render(
  File "django/forms/widgets.py", line 278, in render
    context = self.get_context(name, value, attrs)
  File "django/contrib/admin/widgets.py", line 327, in get_context
    "rendered_widget": self.widget.render(name, value, attrs),
  File "filer/fields/file.py", line 70, in render
    html = render_to_string('admin/filer/widgets/admin_file.html', context)
  File "django/template/loader.py", line 62, in render_to_string
    return template.render(context, request)
  File "django/template/backends/django.py", line 61, in render
    return self.template.render(context)
  File "django/template/base.py", line 171, in render
    return self._render(context)
  File "django/template/base.py", line 163, in _render
    return self.nodelist.render(context)
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/defaulttags.py", line 422, in render
    return strip_spaces_between_tags(self.nodelist.render(context).strip())
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/defaulttags.py", line 326, in render
    return nodelist.render(context)
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/defaulttags.py", line 326, in render
    return nodelist.render(context)
  File "django/template/base.py", line 1000, in render
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 1000, in <listcomp>
    return SafeString("".join([node.render_annotated(context) for node in self]))
  File "django/template/base.py", line 961, in render_annotated
    return self.render(context)
  File "django/template/library.py", line 258, in render
    _dict = self.func(*resolved_args, **resolved_kwargs)
  File "filer/templatetags/filer_admin_tags.py", line 212, in file_icon
    return file_icon_context(file, detail is True, width, height)
  File "filer/templatetags/filer_admin_tags.py", line 157, in file_icon_context
    icon_url = thumbnailer.get_thumbnail(thumbnail_options).url
  File "easy_thumbnails/files.py", line 513, in get_thumbnail
    thumbnail = self.generate_thumbnail(
  File "easy_thumbnails/files.py", line 401, in generate_thumbnail
    img = engine.save_pil_image(
  File "easy_thumbnails/engine.py", line 77, in save_pil_image
    image.save(destination, format=format, **options)
  File "PIL/Image.py", line 2568, in save
    save_handler(self, fp, filename)
  File "PIL/JpegImagePlugin.py", line 642, in _save
    raise OSError(msg) from e

We recently updated Django, Django-CMS, Filter etc. and got this in 2.10. We can go back to 2.0 but we would stuck on Django 5.0.x then.