Merge remote-tracking branch 'origin/tqtc/lts-5.15.7' into tqtc/lts-5.15-opensource

Change-Id: I976ce0c3664c9953dd0019b7d76d3f603583634f

2 files changed, 15 insertions, 2 deletions

diff --git a/src/widgets/widgets/qdockwidget.cpp b/src/widgets/widgets/qdockwidget.cpp
index d9379b0f33..93362f4210 100644
--- a/src/widgets/widgets/qdockwidget.cpp
+++ b/src/widgets/widgets/qdockwidget.cpp
@@ -975,7 +975,7 @@ bool QDockWidgetPrivate::mouseMoveEvent(QMouseEvent *event)
                 > QApplication::startDragDistance()) {
 
 #ifdef Q_OS_MACOS
-            if (windowHandle()) {
+            if (windowHandle() && !q->isFloating()) {
                 // When using native widgets on mac, we have not yet been successful in
                 // starting a drag on an NSView that belongs to one window (QMainWindow),
                 // but continue the drag on another (QDockWidget). This is what happens if
diff --git a/src/widgets/widgets/qscrollarea.cpp b/src/widgets/widgets/qscrollarea.cpp
index f7a4f8e446..f880240ea7 100644
--- a/src/widgets/widgets/qscrollarea.cpp
+++ b/src/widgets/widgets/qscrollarea.cpp
@@ -196,7 +196,20 @@ void QScrollAreaPrivate::updateScrollBars()
     if (resizable) {
         if ((widget->layout() ? widget->layout()->hasHeightForWidth() : widget->sizePolicy().hasHeightForWidth())) {
             QSize p_hfw = p.expandedTo(min).boundedTo(max);
-            int h = widget->heightForWidth( p_hfw.width() );
+            int h = widget->heightForWidth(p_hfw.width());
+            // If the height we calculated requires a vertical scrollbar,
+            // then we need to constrain the width and calculate the height again,
+            // otherwise we end up flipping the scrollbar on and off all the time.
+            if (vbarpolicy == Qt::ScrollBarAsNeeded) {
+                int vbarWidth = vbar->sizeHint().width();
+                QSize m_hfw = m.expandedTo(min).boundedTo(max);
+                while (h > m.height() && vbarWidth) {
+                    --vbarWidth;
+                    --m_hfw.rwidth();
+                    h = widget->heightForWidth(m_hfw.width());
+                }
+                max = QSize(m_hfw.width(), qMax(m_hfw.height(), h));
+            }
             min = QSize(p_hfw.width(), qMax(p_hfw.height(), h));
         }
     }