1428013 - Dragging a tab to a different window sometimes causes images to disappear (with image.mem.shared = true)

Status: VERIFIED FIXED

(Core :: Graphics: WebRender, defect, P1)

Description

[Markus Stange [:mstange]]

20180103230158

Steps to reproduce:
 1. Make sure webrender and image.mem.shared are enabled.
 2. Load a web page with large images in a window with multiple tabs, for example https://www.flickr.com/photos/mozillaallhands/38648163334/in/album-72157690829163904/
 3. Drag the tab with that page downwards in order to move it into its own window.

When the new window opens with the tab, the large image is no longer displayed.

Comment 1

[Andrew Osmond [:aosmond] (he/him)]

Same build, reproducible on Linux too.

Comment 2

[Milan Sreckovic [:milan] (needinfo for best results)]

And it works with image.mem.shared disabled?

Comment 3

[Andrew Osmond [:aosmond] (he/him)]

(In reply to Milan Sreckovic [:milan] from comment #2)
> And it works with image.mem.shared disabled?

Yes. This is related to how a WebRenderBridgeChild is reinitialized during a tab move.

Comment 4

[Andrew Osmond [:aosmond] (he/him)]

Attachment: 0001-Bug-1428013-Ensure-a-shared-surface-s-image-key-is-r.patch

Sotaro, you seem to know the consequences of moving a tab the best :). My understanding is that I don't need to do anything about my old image key because it was already discarded and the cache cleared, so I just need to regenerate a new one if the namespace changes (the signal I am using to determine the tab moved -- let me know if you know about any others.)

Comment 5

[Sotaro Ikeda [:sotaro]]

Yes, keys are already removed by parent side when name space is changed by tab move.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/2150458a2e9d
Ensure a shared surface's image key is recreated during a tab move. r=sotaro

Comment 7

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/mozilla-central/rev/2150458a2e9d

Comment 8

[Catalin Sasca, Desktop QA [:csasca]]

I successfully reproduced this issue on Firefox Nightly 60.0a1 (2018-01-03) under macOS 10.12.6, after a few tries.

The issue is not reproducible on Firefox 59.0 and Firefox Nightly 60.0a1 (2018-03-09) under Ubuntu 16.04 x64, Windows 10 x64, and macOS 10.12.6. 

For the testing on the latest builds, for the pref. image.mem.shared I used value 1, as I read in https://bugzilla.mozilla.org/show_bug.cgi?id=1425260#c2 that value 1 means enabled.