RichTextBlockWithFootnotes no longer respects `WAGTAILADMIN_RICH_TEXT_EDITORS`

[CamLamb]

Simply swapping all RichTextBlocks with RichTextBlockWithFootnotes will remove the existing functionality where RichTextBlocks get their features from WAGTAILADMIN_RICH_TEXT_EDITORS["default"]["OPTIONS"]["features"].

Task:
Update the RichTextBlockWithFootnotes.__init__() to respect the features set by RichTextBlock then append footnotes to that list.

[davidlesieur]

I'm also observing this. When using an editor other than default, I only get the newline and footnotes features. Features specified in WAGTAILADMIN_RICH_TEXT_EDITORS are being completely ignored.

RichTextBlockWithFootnotes.__init__() goes like this:

    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        if not self.features:
            self.features = []
        if "footnotes" not in self.features:
            self.features.append("footnotes")

All super().__init__() does about features is set self.features from kwargs["features"] (which is None in my case).

Then setting self.features = [] appears to be the root of the issue. self.features must be None for features to be later retrieved (at widget creation time) from WAGTAILADMIN_RICH_TEXT_EDITORS. But here RichTextBlockWithFootnotes.__init__() ends up setting self.features to just ["footnotes"], meaning I only get the newline feature (because it's hardcoded) and the footnotes feature.

The problem is easy to understand, but I'm not sure how to solve it elegantly without either abandoning the idea of RichTextBlockWithFootnotes manipulating the features, overriding more of RichTextBlock, or altering a bit how RichTextBlock works.

For now, a workaround is to pass all the desired features to the features argument of __init__().