714709 - Pinch zooming in will display blank content on Ted.com

Status: RESOLVED WORKSFORME

(Core :: Layout, defect, P1)

Description

[Tony Chung [:tchung]]

On certain websites, pinch zooming into the content area will cause a blank screen with only scrollbars present.  Pinch zooming back out will restore the content correctly.

Double tap zooming does not show this problem.

See screencast of repro at: http://youtu.be/j5SSZTrzLMw
Logcat does not have any helpful data.

Repro:
1) install Fennec Nightly 1-2-2011 build, Galaxy Nexus
2) launch ted.com
3) pinch zoom in to any content within the site.  Verify content blanks out and panning around only shows scrollbar.   (see screencast for repro) 

Expected:
- pinch zooming on site should not blank screen\

Actual:
- blank screen after pinch zooming in

Comment 1

[Aaron Train [:aaronmt]]

I can reproduce this. Merely pinch zooming in just a tad yields the entire viewport greyed out.

--
Samsung Nexus S (Android 4.0.3)
Mozilla/5.0 (Android; Linux armv7l; rv:12.0a1) Gecko/20120103 Firefox/12.0a1 Fennec/12.0a1

Comment 2

[Kartikaya Gupta (email:[e-mail])]

Able to repro on Galaxy Tab as well. I see it also happening with double tap zoom though. Seems to happen whenever the zoom is >= ~1.34

Comment 3

[Kartikaya Gupta (email:[e-mail])]

As speculated, this is not specific to Fennec Native. Loading ted.com causes crashes in the latest XUL fennec tinderbox build for me:

bp-1f0c982a-76e9-4559-bebf-9cab52120103
bp-b8ed3911-cce5-47f5-94ed-040ed2120103

I also traced through the Fennec code and the behaviour appears normal on the Fennec side of things; this is likely a core Gecko issue.

Comment 4

[Kartikaya Gupta (email:[e-mail])]

I took a page from the pcwalton playbook and turned on some of the painting dump code in layout/base/nsLayoutUtils.cpp so that I could see what was getting painted. Turns out that when I zoom in, almost nothing is painted except for the background, whereas in the zoomed out state there's a lot of stuff (all the page elements) getting painted. So this definitely appears to be a core layout/graphics issue. I'll attach the dumps I got. Not sure who should be looking at this now.

Comment 5

[Kartikaya Gupta (email:[e-mail])]

Attachment: dump from zoomed-in state where ted.com doesn't render

Comment 6

[Kartikaya Gupta (email:[e-mail])]

Attachment: dump from zoomed-out state where ted.com DOES render

Comment 7

[Jet Villegas (inactive)]

http://www.ted.com/css/global.css

A single line of *sketchy* CSS is causing this error on zoom in Fennec:

text-indent: -9999999px; 

It seems like we need a clamp in there somewhere.

Comment 8

[Doug Turner (:dougt)]

lolz

Comment 9

[Joe Drew (not getting mail)]

Jeff, I have a memory of you working on some clamping/etc, but don't remember which bug that is. Helpplz?

Comment 10

[Jeff Muizelaar [:jrmuizel]]

(In reply to Joe Drew (:JOEDREW!) from comment #9)
> Jeff, I have a memory of you working on some clamping/etc, but don't
> remember which bug that is. Helpplz?

I have no recollection of this.

Comment 11

[Jeff Muizelaar [:jrmuizel]]

(In reply to Jeff Muizelaar [:jrmuizel] from comment #10)
> (In reply to Joe Drew (:JOEDREW!) from comment #9)
> > Jeff, I have a memory of you working on some clamping/etc, but don't
> > remember which bug that is. Helpplz?
> 
> I have no recollection of this.

Joe reminded me in more detail what he was talking about. Checking whether analyze_extent() in pixman.c ever returns FALSE would confirm that these problems are related.

Comment 12

[Joe Drew (not getting mail)]

Jeff thinks this is the same issue as bug 671302. If it is (i.e., if analyze_extent() returns FALSE), there's no easy fix; we need to find a way to not pass huge coordinates to pixman/cairo. 

Fixing that, unfortunately, lies wholly in layout's realm.

Comment 13

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Why?  We've had things like ConditionRect in gfx code in the past.  It seems far easier to do it in a small number of places than a large number of places.

Comment 14

[Joe Drew (not getting mail)]

Jeff will need to answer, but the problem AIUI is basically that we don't know where to wrap, but layout folk might.

Comment 16

[Kartikaya Gupta (email:[e-mail])]

bug 716970 is also an issue that suffers from excessive negative text-indent, in that case -999em. I marked it as a duplicate of this; there is a test page at http://people.mozilla.com/~kgupta/bug/716970/original/so-bluebg.html where zooming in and scrolling causes the background to turn blue. There is also a modified version at http://people.mozilla.com/~kgupta/bug/716970/modified/so-bluebg.html with that one line of CSS removed, which doesn't have the blue background problem.

I reproduced this on a Galaxy Tab 10.1 running a personal build of Fennec Native taken from very recent m-c.

Comment 18

[Jet Villegas (inactive)]

(In reply to Joe Drew (:JOEDREW!) from comment #12)
> Jeff thinks this is the same issue as bug 671302. If it is (i.e., if
> analyze_extent() returns FALSE), there's no easy fix; we need to find a way
> to not pass huge coordinates to pixman/cairo. 
> 
> Fixing that, unfortunately, lies wholly in layout's realm.

I put a LOG in pixman.c and analyze_extent() does _not_ return FALSE in this case. We need another bottleneck to trap this. Ideas?

Comment 19

[Joe Drew (not getting mail)]

Jeff, can you spend 2 hours to find out what's causing this? Layout is reticent to put a fix into the CSS parser and would prefer a general solution in the rasterizer.

Comment 20

[Aaron Train [:aaronmt]]

Fennec is having issues rendering Facebook with sketchy CSS too; i.img u{position:absolute;top:-9999999px} -- bug 727453.

Comment 21

[Aaron Train [:aaronmt]]

Testcase: https://bugzilla.mozilla.org/attachment.cgi?id=597840

Comment 23

[Jet Villegas (inactive)]

Changed the bug title given the latest symptoms. We definitely don't want to clamp these at the CSS level.

Comment 24

[Martijn Wargers (dead)]

Can this also crashes like bug 728269?

Comment 26

[Doug Turner (:dougt)]

does this happen on the Maple twig?

Comment 27

[Aaron Train [:aaronmt]]

I cant reproduce with the 02/23 Maple nightly. Tested on a Galaxy Nexus; also tested Facebook (bug 728554).

Comment 28

[Tony Chung [:tchung]]

I can't reproduce this anymore.   on a 2/27/2012 trunk nightly, using a HTC Sensation.   Pinch zooming in and out on ted.com is working properly.   Granted, there's checkerboarding, but its still displaying content as you would expect.  

If anyone else can't reproduce either, i'll mark this bug WFM.

Comment 29

[Camelia Urian]

Verified on latest 
Nightly 13.0a1 (2012-02-27) 
Samsung Nexus S - Android 2.3.6

Could not reproduce issue.

Comment 30

[Sam Tobin-Hochstadt [:samth]]

I can still reproduce bug 716970, following Kartikaya's instructions in the last comment there.  This is with latest Nightly (ie, I downloaded it 1 minute ago), on HTC Sensation, Android 2.3.4.

Comment 31

[Kartikaya Gupta (email:[e-mail])]

It could be that ted.com no longer has the css in question, but we still have the bug. We should keep this open and use str that don't depend on a live website.

Comment 33

[Paul Feher]

I can still reproduce this on gsp.ro using:

Nightly 14.0a1 (2012-03-22) 
HTC Desire - Android 2.2.2

Comment 35

[Mark Finkle (:mfinkle) (use needinfo?)]

The number of dupes and the sites where this happens warrants blocking beta

Comment 36

[Tony Chung [:tchung]]

4-16-2012 nightly fennec, HTC Sensation Android 2.3.4.

Ted.com isnt reproducing this problem anymore.  tried site from comment 33, and i can't reproduce there either.

Comment 37

[Patrick Walton (:pcwalton)]

(In reply to Mark Finkle (:mfinkle) from comment #35)
> The number of dupes and the sites where this happens warrants blocking beta

Are you referring to black screens? I've seen that, but not this problem.

Comment 38

[Aaron Train [:aaronmt]]

Attachment: Nightly (04/17) - GN: 4.0.4 Screenshot

(In reply to Aaron Train [:aaronmt] from comment #21)
> Testcase: https://bugzilla.mozilla.org/attachment.cgi?id=597840

Seen today --

Comment 39

[Aaron Train [:aaronmt]]

(In reply to Patrick Walton (:pcwalton) from comment #37)
> (In reply to Mark Finkle (:mfinkle) from comment #35)
> > The number of dupes and the sites where this happens warrants blocking beta
> 
> Are you referring to black screens? I've seen that, but not this problem.

Pinch-zoom in my test-case (ignore instruction in test-case, mistake).

Comment 40

[Tony Chung [:tchung]]

(In reply to Paul Feher from comment #33)
> I can still reproduce this on gsp.ro using:
> 
> Nightly 14.0a1 (2012-03-22) 
> HTC Desire - Android 2.2.2

Paul, can you try and reproduce this again on latest build?  Also, specify good repro steps, logcat, and screenshots.   We're trying to track down how widespread this problem is.   

Also, confirm Aaron's testcase in comment 21 if possible.

Comment 41

[JP Rosevear [:jpr]]

Bas is looking, QA is also going to help recheck the test cases against what just merged to central recently, which has several layout fixes.

Comment 42

[Aaron Train [:aaronmt]]

With the inbound-build at ftp://ftp.mozilla.org/pub/mobile/tinderbox-builds/mozilla-inbound-android/1334371573/ containing a few recent layout fixes, I'm finding it hard to reproduce. Looks like that build contains a fix.

Comment 43

[JP Rosevear [:jpr]]

Bas could also not reproduce this.  Aaron nom'ed other bugs because there are still some visual artifacts.

Comment 44

[JP Rosevear [:jpr]]

Re-noming as per #43

Comment 45

[Naoki Hirata :nhirata (please use needinfo instead of cc)]

I can't seem to reproduce this on today's build.  4/18/2012.
It does go blank for a moment on youtube.com, but then it appears.

Tested on : Droid 2, Nexus S, Galaxy Nexus

Comment 46

[Tony Chung [:tchung]]

qawanted is left here for now, so we can re-review qawanted on the bugs dupe'd to this one.

Comment 47

[Tony Chung [:tchung]]

comment 21 is fixed