Fix QListWidget item widget scroll bug

This fix applies the patch uploaded in the bug report. The patch was
provided by Qt-Commercial support but seems to have never found it's
way to the sources although the bug was fixed in Qt 5.

Task-number: QTBUG-27043
Change-Id: I41c5a7b8f3698bb4396046e5e74863e090ba185a
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>

1 files changed, 1 insertions, 3 deletions

diff --git a/src/gui/kernel/qwidget_mac.mm b/src/gui/kernel/qwidget_mac.mm
index 2fe1f06..efd2ff2 100644
--- a/src/gui/kernel/qwidget_mac.mm
+++ b/src/gui/kernel/qwidget_mac.mm
@@ -4723,14 +4723,12 @@ void QWidgetPrivate::scroll_sys(int dx, int dy, const QRect &qscrollRect)
 
     // Scroll the whole widget if qscrollRect is not valid:
     QRect validScrollRect = qscrollRect.isValid() ? qscrollRect : q->rect();
-    validScrollRect &= clipRect();
 
     // If q is overlapped by other widgets, we cannot just blit pixels since
     // this will move overlapping widgets as well. In case we just update:
     const bool overlapped = isOverlapped(validScrollRect.translated(data.crect.topLeft()));
     const bool accelerateScroll = accelEnv && isOpaque && !overlapped;
     const bool isAlien = (q->internalWinId() == 0);
-    const QPoint scrollDelta(dx, dy);
 
     // If qscrollRect is valid, we are _not_ supposed to scroll q's children (as documented).
     // But we do scroll children (and the whole of q) if qscrollRect is invalid. This case is
@@ -4752,7 +4750,6 @@ void QWidgetPrivate::scroll_sys(int dx, int dy, const QRect &qscrollRect)
         }else {
             update_sys(qscrollRect);
         }
-        return;
     }
 
 #ifdef QT_MAC_USE_COCOA
@@ -4769,6 +4766,7 @@ void QWidgetPrivate::scroll_sys(int dx, int dy, const QRect &qscrollRect)
     // moved when the parent is scrolled. All directly or indirectly moved
     // children will receive a move event before the function call returns.
     QWidgetList movedChildren;
+    const QPoint scrollDelta(dx, dy);
     if (scrollChildren) {
         QObjectList children = q->children();