Notification for PDF containing forms with pref enabled still displayed on some files

[cfogelSV]

Affected versions

• 81.0a1 (2020-08-16)

Affected platforms

• Windows 10, macOS 11.0, Ubuntu 16;

Steps to reproduce
pdfjs.renderInteractiveForms - enabled

1. Launch Firefox;
2. Access a PDF form with fillable content such as link;
3. Click inside any field, start filling in data;

Expected result

• data is filled, no unexpected warning notifications appear;

Actual result

• warning banner for [Document containing forms & Filling of forms unsupported] is displayed;

Additional notes:

• S3 as suggested severity;
• attached screenshot with the issue;

[Snuffleupagus]

This is expected, note #12201 (comment), and this issue is for all intents and purposes thus a duplicate of e.g. issue #2373.

[timvandermeij]

Thinking about this a bit more, I think we should just ignore XFA for now since it's tracked in another issue and it's not blocking the filling/saving/printing of AcroForm forms. If both occur in a PDF document, we can remove the fallback bar and log a warning that XFA features are unsupported. AFAICT they are an extension and not vital for filling in forms, and looking at the above issue it's not likely to be implemented anytime soon, so showing the fallback bar in those cases seems incorrect.