1583090 - distorted image (scaled version of part of image) when large image is partially visible when going back to page (restoring from bfcache)

Status: RESOLVED DUPLICATE of bug 1580922

(Core :: Graphics: WebRender, defect, P2)

Description

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: about:support

This bugs happens for me with WebRender enabled, but if I force-disable WebRender the bug goes away.

Steps to reproduce:

1. load https://www.nhc.noaa.gov/
2. scroll down so the main map image is mostly offscreen (i.e., just the bottom hundred pixels or so is visible)
3. click a link to one of the text statements (e.g., "Public Advisory #4", "Forecast Discussion #4", etc.)
4. press the keyboard shortcut for back (e.g., Alt + <- on Linux)
5. scroll up

Actual results:
after 4: distorted version of map image visible (part of the image is scaled up vertically)
after 5: distortion changes (still same underlying scaling, but different amounts)

Expected results: no distortion/scaling

I think if I look closely there's also some distortion visible during smooth scroll in some cases (maybe involving switching windows) even before the "go to a different page" step.

The result of mozregression gives this regression range, implicating bug 1568227.

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: screenshot

Comment 2

[Jeff Muizelaar [:jrmuizel]]

This is likely a dup of 1580922

Comment 3

[Julien Cristau [:jcristau]]

David can you confirm this is now fixed in nightly? (bug 1580922 was resolved last week)

Comment 4

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Yes, this looks fixed.