Bug 101242 (Stephen)

Summary: flash rendering messed up when web page is scrolled.
Product: WebKit Reporter: Stephen <sfcheng>
Component: WebKit QtAssignee: Nobody <webkit-unassigned>
Severity: Critical CC: nilsfromparis, sfcheng
Priority: P1    
Version: 528+ (Nightly build)   
Hardware: PC   
OS: Windows 7   
URL: http://finance.yahoo.com/echarts?s=%5EGSPC+Interactive#symbol=%5Egspc;range=1d;compare=;indicator=volume;charttype=area;crosshair=on;ohlcvalues=0;logscale=off;source=undefined;
Description Flags
screenshot of yahoo finance flash content when messed up. none

Description Stephen 2012-11-05 11:48:55 PST
Created attachment 172372 [details]
screenshot of yahoo finance flash content when messed up.

On many sites with flash video or other flash content, when the web page is scrolled up or down, the rendering of the flash content is completely messed up. Part of the content could be even rendered outside the designated element boundary. This issue has started since QT 4.8.0 and remains in QT 4.8.3. It happens to the Windows platform only. Here are a few example pages:

1. Yahoo finance stock chart: http://finance.yahoo.com/echarts?s=%5EGSPC+Interactive#symbol=%5Egspc;range=1d;compare=;indicator=volume;charttype=area;crosshair=on;ohlcvalues=0;logscale=off;source=undefined; 
2. http://www.nrc.nl/nieuws/2012/08/06/terugkijken-zomergasten-afgebroken-na-migraine-aanval-jolande-withuis/?utm_campaign=rss&utm_source=syndication 
3. http://video.sina.com.cn/p/news/s/v/2012-01-09/071861635853.html?opsubject_id=top1

Hopefully somebody can get their hands on this issue. This issue is very prevalent and appears on a long list of websites. I have to stick to Qt 4.7.4 so far due to this major bug. 

A screenshot is attached to illustrate what it looks when the stock chart is messed up on yahoo finance after scrolling.
Comment 1 Nils Dupont 2012-11-12 03:56:06 PST
I confirm that this bug happens with Qt4.8.3 "QtWebKit4.dll" on Windows platform.
If I use Qt4.7.4 "QtWebKit4.dll", this bug doesn't happen anymore.
Comment 2 Nils Dupont 2012-11-12 03:59:55 PST
This bug is maybe linked to this "closed" bug:


When a Flash swf is embedded in page with a "wmode" different from "windows" (e.g. "opaque" or "transparent"), these rendering issues happen with qtwebkit 2.2.2 included in Qt4.8.3.

Comment 3 Stephen 2012-11-12 13:01:09 PST
I applied the patch mentioned in https://bugs.webkit.org/show_bug.cgi?id=92905. The flash rendering issues mentioned in the three testing pages are resolved after applying the patch. Great fix! I hope this patch can be incorporated into QT 4.8.4.

*** This bug has been marked as a duplicate of bug 92905 ***