diff -r 067bc37b0508 Qt-4.8.0/src/gui/widgets/qabstractscrollarea.cpp
--- a/Qt-4.8.0/src/gui/widgets/qabstractscrollarea.cpp	Fri Jan 23 10:29:40 2015 +0300
+++ b/Qt-4.8.0/src/gui/widgets/qabstractscrollarea.cpp	Fri Mar 20 11:08:44 2015 +0300
@@ -430,11 +430,9 @@
     // no corner widget. Also, on the Mac we paint if there is a native
     // (transparent) sizegrip in the area where a corner widget would be.
     if ((needv && needh && hasCornerWidget == false)
-        || ((needv || needh) 
 #ifdef Q_WS_MAC
-        && hasMacSizeGrip
+        || hasMacSizeGrip
 #endif
-        )
     ) {
         cornerPaintingRect = QStyle::visualRect(opt.direction, opt.rect, QRect(cornerPoint, extSize));
     } else {