STEPS: use any data URL in HTML or in URL bar that has invalid parameters. OBSERVED data: will fail to processes EXPECTED some kind of error notification. I think a dialog would be overkill, but based on my experience from reviewing the RFC and writing a test suite, data: URLs do not give any feedback when they fail to process. It would be nice to see a couple basic error messages for the following conditions: "No data" - common because you need a comma after parameters, before the data. "Decode failure" - from bad base64 encoded data. "Character set unavailable" - for incorrect or missing character set references in the "media "section.

mass reassigning to nobody.

Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258