Bug 92902

Summary: [Qt][WK2] Race condition between first layout and viewport attributes initialization
Product: WebKit Reporter: Jesus Sanchez-Palencia <jesus>
Component: WebKit QtAssignee: Jesus Sanchez-Palencia <jesus>
Status: RESOLVED FIXED    
Severity: Normal CC: abecsi, cmarcelo, menard, webkit.review.bot, zoltan
Priority: P2 Keywords: Qt, QtTriaged
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Patch none

Jesus Sanchez-Palencia
Reported 2012-08-01 12:53:41 PDT
During our WebView initialization a default FrameView is created, triggering a layout. This is triggering QtViewportHandler::pageContentsSizeChanged earlier than the first QtViewportHandler::viewportAttributesChanged, which was responsible for initializing m_rawAttributes from QtViewportHandler. This hasn't been noticed before because we set useFixedLayout in QQuickWebViewFlickablePrivate::initialize before the layout is finished, which triggers the correct layout anyway. However, while debugging https://bugs.webkit.org/show_bug.cgi?id=92753, debug messages delayed the initialization of the webview and the first layout finished before expected, leading us to "ASSERT(scale < 0)" in QQuickWebPage::setContentsScale. (The random negative scale was returned by WebCore::computeMinimumScaleFactorForContentContained, called in QtViewportHandler::pageContentsSizeChanged). This overly descriptive bug report is for the sake of remembering, since it took me a while to understand the race condition... Patch is coming.
Attachments
Patch (2.08 KB, patch)
2012-08-01 13:38 PDT, Jesus Sanchez-Palencia 		no flags
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
Jesus Sanchez-Palencia
Comment 1 2012-08-01 13:38:32 PDT
Created attachment 155874 [details] Patch
WebKit Review Bot
Comment 2 2012-08-01 15:21:16 PDT
Comment on attachment 155874 [details] Patch Clearing flags on attachment: 155874 Committed r124374: <http://trac.webkit.org/changeset/124374>
WebKit Review Bot
Comment 3 2012-08-01 15:21:20 PDT
All reviewed patches have been landed. Closing bug.
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