1293692 - [e10s] Ctrl+Tab thumbnails sometimes rendered as black

Status: RESOLVED FIXED

(Firefox :: Tabbed Browser, defect, P3)

Description

[Dão Gottwald [:dao]]

Not sure what exactly is going on here, but I think we're probably triggering the snapshot update at the wrong time.

Also, I think this is a regression.

Comment 1

[Dão Gottwald [:dao]]

STR:

0. enable "Ctrl+Tab cycles through tabs in recently used order" in a new profile
1. open a new tab
2. accel+click on the "Mozilla Developer Network" tile
3. press ctrl+tab and keep ctrl pressed while MDN is loading

-> the thumbnail updates a few times while the page is loading but the final image is all black

This only happens with e10s.

Comment 2

[Tracy Walker [:tracy]]

I can reproduce this on Mac 10.11 with Nightly 51.0a1, 20160817030202.

When was this feature introduced?

I'll dig up a regression range.

Comment 3

[Dão Gottwald [:dao]]

(In reply to Tracy Walker [:tracy] from comment #2)
> When was this feature introduced?

It's been around for a long time but behind a hidden pref: browser.ctrlTab.previews

Comment 4

[Gerry Chang [:gchang]]

Mark 51 as fix-optional by P3.

Comment 5

[Ryan VanderMeulen [:RyanVM]]

Any progress here, Tracy?

Comment 6

[Tracy Walker [:tracy]]

The regression range is nearly 2 years ago.  I wasn't able to use mozregression to track this down. mozregression wasn't fully respecting prefs set to make sure this is reproducible.  builds with mozregression were not displaying suggested site tiles. So a manual one day regression range was all I could dig up.

last good build: 20150122030202
first buggy build: 20150123030203

This is a polish bug. The black tile persist only for the duration of holding ctrl in step 3.  If you release ctrl and retrigger (ctrl+tab) the tab preview and the previously black thumbnail correctly contains a content preview.

Comment 7

[:Gijs (he/him)]

(In reply to Tracy Walker [:tracy] from comment #6)
> The regression range is nearly 2 years ago.  I wasn't able to use
> mozregression to track this down. mozregression wasn't fully respecting
> prefs set to make sure this is reproducible.  builds with mozregression were
> not displaying suggested site tiles. So a manual one day regression range
> was all I could dig up.
> 
> last good build: 20150122030202
> first buggy build: 20150123030203
> 
> This is a polish bug. The black tile persist only for the duration of
> holding ctrl in step 3.  If you release ctrl and retrigger (ctrl+tab) the
> tab preview and the previously black thumbnail correctly contains a content
> preview.

Based on that, maybe bug 1088203? Dão, does that help?

Comment 8

[:Gijs (he/him)]

(Looking at https://hg.mozilla.org/mozilla-central/pushloghtml?startdate=2015-01-22&enddate=2015-01-23, fwiw, which might not be entirely accurate... revisions would be better than dates, but it's late - I can look again if comment 7 is a terrible guess and we need a more accurate pushlog to keep looking)

Comment 9

[Dão Gottwald [:dao]]

(In reply to :Gijs from comment #7)
> Based on that, maybe bug 1088203? Dão, does that help?

Quite possible. Bug 1088203 adds async messages, changing the timing around when exactly we'd take a screenshot and perhaps exposing a race condition. The underlying issue that we get a black thumbnail when taking the screenshot at the "wrong" time is likely older and not a bug in front-end code.

Comment 10

[Andrew Overholt [:overholt]]

Non-default behaviour => fix-optional.

Comment 12

[Monica Chiorean]

Attachment: Screnshoot_98.0b2.jpg

Affected versions

• Beta 98.0b2 (64-bit)
• NB 99.0a1 (20220209190711)

Affected platforms
Win10 / Ubuntu 20.4

Issue still reproduced on above builds and OSs (meaning that when first pressing Ctrl+Tab, after enabling "Ctrl+Tab cycles through tabs in recently used order" there are still tabs that have a dark background and no text - see screenshot attached; second time I press all tabs have text). see bug 1752729.

Comment 13

[Shane Hughes [:aminomancer]]

Attachment: Bug 1293692 - Update ctrlTab thumbnails asynchronously. r=dao

Comment 14

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/d6e93c10a90d
Update ctrlTab thumbnails asynchronously. r=dao

Comment 15

[Sandor Molnar]

https://hg.mozilla.org/mozilla-central/rev/d6e93c10a90d