I noticed that yelp was also complaining about missing help-browser icon until today when it started using native AppStream metadata instead of letting appstream-generator create the basic metadata from its .desktop. So maybe we could fix this bug sooner by creating that metadata file and including it in the firefox and thunderbird binary packages.
Otherwise, I think this bug might be fixed when we get a newer version of appstream-generator installed in the Ubuntu server that provides the metadata downloads.
I noticed that yelp was also complaining about missing help-browser icon until today when it started using native AppStream metadata instead of letting appstream-generator create the basic metadata from its .desktop. So maybe we could fix this bug sooner by creating that metadata file and including it in the firefox and thunderbird binary packages.
Otherwise, I think this bug might be fixed when we get a newer version of appstream-generator installed in the Ubuntu server that provides the metadata downloads.