808204 - Often get a corrupted region after clicking a link on Reddit

Status: RESOLVED WORKSFORME

(Core :: Layout, defect)

Description

[Justin Dolske [:Dolske]]

Attachment: Screenshot of corruption

[Thought I'd already filed this, but was thinking of bug 795648. The effect is similar, maybe related?]

Often when clicking links on Reddit the clicked link text will become garbled. Pretty sure this started happening right after dlbi landed. Seems to happen more frequently when command-clicking image links to open them in a background tab.

A possibly useful tidbit: Reddit uses onmousedown JS to change the link color from blue to purple -- it's not the normal visited-link coloring the browser does. You can see this by pressing-and-holding the mouse on a link -- it immediately changes color without the browser having even started a page load.

Comment 1

[Justin Dolske [:Dolske]]

Attachment: Screenshot (normal)

Comment 2

[Justin Dolske [:Dolske]]

Attachment: Worse.

Comment 3

[Justin Dolske [:Dolske]]

(actually I that that's bug 806661)

Comment 4

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Reproducible? Still happening?

Comment 5

[Alex Keybl [:akeybl]]

Juan - are you able to reproduce?

Comment 6

[Matt Woodrow (:mattwoodrow)]

This is almost definitely a dup of bug 795648.

That bug was us modifying layout (via synchronous image coding) during painting which caused us to abort the paint.

In that bug that aborted paint was the tabstrip, but aborting content paints sounds like the exact same issue.

Comment 7

[Alex Keybl [:akeybl]]

Please re-nominate if this bug is still occurring in FF18 after bug 795648 landed.

Comment 8

[Justin Dolske [:Dolske]]

Hmm, I'm still seeing this with yesterday's nightly...

http://cl.ly/image/0Q0v1N1K3J1h the garbled stuff there is a link to http://i.imgur.com/OPpNH.png. As in comment 0, I was command-clicking links to open a sequence of images in new tabs (this is /r/minecraft of reddit, people post a lot of screenshots).

Comment 9

[Matt Woodrow (:mattwoodrow)]

Bizarre. That definitely sounds like the same issue, which should have been fixed.

Would you be willing to test with a local build with this warning:

http://mxr.mozilla.org/mozilla-central/source/layout/base/FrameLayerBuilder.cpp#3398

Changed to a runtime assertion.

That seems like the most obvious cause of broken painting, confirming it would be useful.

Comment 10

[Matt Woodrow (:mattwoodrow)]

Actually, just a build with this patch applied:

https://bugzilla.mozilla.org/attachment.cgi?id=682208

Would probably be the best.

Comment 11

[Alex Keybl [:akeybl]]

Hopefully testing with the warning enabled will help us find the root cause, although we won't block the release on this issue.

Juan - are you able to repro?

Comment 12

[juan becerra [:juanb]]

I have been trying to reproduce this for the last couple of days on hardware that I have, and I have not been able to reproduce this on reddit. There's no mention of hardware here, and I don't know if this would have anything to do with machines with Retina displays, but if you have any other suggestions or information I can use, it would be very helpful.

Marcia, can you give it a try on your machine with Retina?

Comment 13

[Marcia Knous [:marcia]]

Justin: Do you have any addons installed at all? I gave a brief pass command clicking a bunch of reddit links and have not seen it so far.

Comment 14

[Justin Dolske [:Dolske]]

(In reply to Matt Woodrow (:mattwoodrow) from comment #10)
> Actually, just a build with this patch applied:
> 
> https://bugzilla.mozilla.org/attachment.cgi?id=682208

I ran a build with this, and spent an entertaining 20 minutes or so clicking lots of image links on various subreddits. Alas, I wasn't able to reproduce the bug. :(

I've only seen it a few times in normal usage, so maybe this is just very very rare. (At least since around when bug 795648 landed, before that I saw this bug frequently).

Comment 15

[bhavana bajaj [:bajaj]]

Marking this as resolved, WFM as per comment 14 & removing it from tracking-firefox-18 as this would not block the release .Feel free to reopen & nominate if this happens again.