379485 - [FIX]Don't render a page before the stylesheet is loaded

Status: VERIFIED FIXED

(Core :: CSS Parsing and Computation, defect, P1)

Description

[Peter van der Woude [:Peter6]]

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9a5pre) Gecko/20070501 Minefield/3.0a5pre ID:2007050121 [cairo]

since bug 84582 landed some pages flicker during initial rendering.

the cause is that they are renderd before the stylesheet is actually loaded.

visable a.o. http://www.cnn.com/ and http://forums.mozillazine.org/

Comment 1

[Boris Zbarsky [:bzbarsky]]

Can you create a testcase?  The current code _does_ hold off rendering until the sheets have loaded.

Comment 2

[Boris Zbarsky [:bzbarsky]]

And more to the point, this worksforme.  Are you using any extensions that would be querying layout information about the page before onload fires?

Comment 3

[Steve England [:stevee]]

Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9a5pre) Gecko/20070502 Minefield/3.0a5pre ID:2007050204 [cairo]
I can reproduce this semi-reliably at http://fileforum.betanews.com/ with a new profile. CTRL-F5 if you can't see it, but the page initially loads without styling before assuming its styled look.

Comment 4

[Boris Zbarsky [:bzbarsky]]

Interesting.  I definitely cannot reproduce on http://fileforum.betanews.com/, with either normal reload or shift-reload....

Can someone reproduce this in a build with debug symbols?  If so, I would be interested in seeing the stack to PresShell::InitialReflow.

Comment 5

[Boris Zbarsky [:bzbarsky]]

Ah, I managed to catch this in a debugger.

We have a bit of a problem.  The issue is that when a subframe load starts it flushes out layout on the parent document in nsDocShell::GetPositionAndSize (called from nsDocShell::SetupNewViewer).

This is probably suboptimal in any case; we shouldn't need to flush here, imho (unlike most callers of GetPositionAndSize, etc).

Comment 6

[Boris Zbarsky [:bzbarsky]]

Attachment: Let's try this

Comment 7

[Johnny Stenback (:jst)]

Comment on attachment 263495 [details] [diff] [review]
Let's try this

r+sr=jst

Comment 8

[Boris Zbarsky [:bzbarsky]]

Checked in.  Thank you for the pointers to testcases!

Comment 9

[Peter van der Woude [:Peter6]]

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9a5pre) Gecko/20070502 Minefield/3.0a5pre ID:2007050214 [cairo] (above patch included)

I'm still seeing the problem when I do a hard reload on Mozillazine forums.

Comment 10

[Peter van der Woude [:Peter6]]

ok, i figured it out.
It's the tab sidebar extension giving some trouble.
w/o it it's fine

->Verified