SVN commit 1089160 by ggarand:

automatically merged revision 1089159:
Critical performance fix:

There is a huge difference of behaviour between DEBUG and RELEASE
builds of Qt 4.6, that breaks scrolling in KHTML.

Using QWidget::scroll() on a widget that doesn't have WA_OpaquePaintEvent
attribute set works just fine in Debug, but completely breaks down in
Release, causing the whole view to get repainted always.


CCMAIL: kde-packager@kde.org

 M  +6 -0      khtmlview.cpp  


--- branches/KDE/4.4/kdelibs/khtml/khtmlview.cpp #1089159:1089160
@@ -604,6 +604,12 @@
         setWidget( new QWidget(this) );
     widget()->setAttribute( Qt::WA_NoSystemBackground );
 
+    // Do *not* remove this attribute frivolously.
+    // You might not notice a change of behaviour in Debug builds
+    // but removing opaque events will make QWidget::scroll fail horribly
+    // in Release builds.
+    widget()->setAttribute( Qt::WA_OpaquePaintEvent );
+
     verticalScrollBar()->setCursor( Qt::ArrowCursor );
     horizontalScrollBar()->setCursor( Qt::ArrowCursor );