1158323 - Many "Attempting to get a margins-based displayport with no base data!" warnings in console on OS X with APZ

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

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

Attachment: Backtrace

I see this warning a bunch when running on OS X with APZ enabled. It fires on the root content element of the root XUL document, see backtrace.

Comment 1

[Botond Ballo [:botond]]

We should probably just call nsLayoutUtils::SetDisplayPortBase() in ChromeProcessController::InitializeRoot().

Comment 2

[Timothy Nikkel (:tnikkel)]

That would be good. We could also set the display port base in the BuildDisplayList of one of the frames near near the root, the root (viewport frame) perhaps.

Comment 3

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

mContent appears to be null inside nsViewportFrame::BuildDisplayList so I'm not sure how we could set the displayport base there.

Comment 4

[Timothy Nikkel (:tnikkel)]

Yeah, we would have to specifically use the root element in that case (instead of mContent).

Comment 5

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

Attachment: Patch

Comment 6

[Botond Ballo [:botond]]

Comment on attachment 8598222 [details] [diff] [review]
Patch

Review of attachment 8598222 [details] [diff] [review]:
-----------------------------------------------------------------

Maybe add a comment in InitalizeRoot, saying where the base rect will be set?

Comment 7

[Timothy Nikkel (:tnikkel)]

Comment on attachment 8598222 [details] [diff] [review]
Patch

I think I have a better way to do it. If there is a root scroll frame in the same document as the viewport frame then we would end up setting the display port base twice, once in the viewport frame, and once in the scroll frame.

Refering to http://mxr.mozilla.org/mozilla-central/source/layout/base/nsCSSFrameConstructor.cpp#2722 I think we should set the display port base in nsRootBoxFrame. That way we only set it in xul documents that don't have root scroll frames.

One nit: we should set the base to the dirty rect intersected with our local rect.

Comment 8

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

Attachment: Patch

Sounds good, this works too.

Comment 9

[Timothy Nikkel (:tnikkel)]

Comment on attachment 8598636 [details] [diff] [review]
Patch

Thanks.

Comment 10

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/18db17b9f922

Comment 11

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/18db17b9f922