728028 - simile timeplot display regressed between firefox 10 and 12

Status: VERIFIED FIXED

(Core :: Graphics: Canvas2D, defect)

Description

[Axel Hecht]

The timeplot we use on the l10n dashboard doesn't show up correctly on aurora and nightly, but works fine on 10.

https://l10n-stage-sj.mozilla.org/dashboard/tree-status/fx_aurora?&bound=7&hideBad shows that, the grey graph seems to be upside down.

Filing in canvas as that's what's actually drawing, didn't do a ton of investigation myself so far.

Comment 1

[Boris Zbarsky [:bzbarsky]]

m-c regression range seems to be http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=005488525c43&tochange=402b394b6623

Unfortunately, there's a huge number of changes in there.  :(

Comment 2

[Boris Zbarsky [:bzbarsky]]

Axel, are you on Mac?  I can't seem to reproduce this on Linux, but I do see it on Mac...

Comment 3

[Axel Hecht]

Yes, I'm on mac.

Comment 4

[Boris Zbarsky [:bzbarsky]]

Yeah, definitely not reproducible on Linux.  I guess we get to bisect on Mac.  :(

Comment 5

[Boris Zbarsky [:bzbarsky]]

The first bad revision is:
changeset:   85317:3c47bcef2ce4
user:        Jeff Muizelaar <[e-mail]>
date:        Tue Jan 24 15:14:50 2012 -0500
summary:     Bug 720721. Properly transform the clip path in DrawTargetCG. r=mwoodrow

Comment 6

[Johnathan Nightingale [:johnath]]

Jeff M - this looks like a novel regression in FF12 from some of your work. tracking-firefox12+ and can you tell us the cost of backing out the offending changeset, and/or suggest some other remedy?

Comment 7

[Jeff Muizelaar [:jrmuizel]]

Attachment: Another rememdy

When we fixed transformed clips it caused us to double transform gradients. We fix this by avoiding ::PushClip when drawing gradients. This has the advantage of saving a save and restore pair and it makes Fill() more closely match Stroke()

Comment 8

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/0de785d6345a

Comment 9

[Axel Hecht [:Pike]]

Verified on nightly.

Should this be uplifted?

Comment 10

[Jeff Muizelaar [:jrmuizel]]

Comment on attachment 599878 [details] [diff] [review]
Another rememdy

[Approval Request Comment]
Regression caused by (bug #): 720721
User impact if declined: Gradients may draw in the wrong spot
Testing completed (on m-c, etc.): on m-c, test case included
Risk to taking this patch (and alternatives if risky): Low, the new code is easier to reason about than the old code
String changes made by this patch: none

Comment 11

[Alex Keybl [:akeybl]]

Comment on attachment 599878 [details] [diff] [review]
Another rememdy

[Triage Comment]
Low risk, verified fix for Aurora 12.

Comment 12

[Jeff Muizelaar [:jrmuizel]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/086fa692e38b