1 files changed, 53 insertions, 4 deletions

diff --git a/src/widgets/itemviews/qlistview.cpp b/src/widgets/itemviews/qlistview.cpp
index b7a4ec3925..9b07564db9 100644
--- a/src/widgets/itemviews/qlistview.cpp
+++ b/src/widgets/itemviews/qlistview.cpp
@@ -53,6 +53,8 @@
 
 QT_BEGIN_NAMESPACE
 
+extern bool qt_sendSpontaneousEvent(QObject *receiver, QEvent *event);
+
 /*!
     \class QListView
 
@@ -796,6 +798,35 @@ void QListView::mouseReleaseEvent(QMouseEvent *e)
     }
 }
 
+#ifndef QT_NO_WHEELEVENT
+/*!
+  \reimp
+*/
+void QListView::wheelEvent(QWheelEvent *e)
+{
+    Q_D(QListView);
+    if (e->orientation() == Qt::Vertical) {
+        if (e->angleDelta().x() == 0
+            && ((d->flow == TopToBottom && d->wrap) || (d->flow == LeftToRight && !d->wrap))
+            && d->vbar->minimum() == 0 && d->vbar->maximum() == 0) {
+            QPoint pixelDelta(e->pixelDelta().y(), e->pixelDelta().x());
+            QPoint angleDelta(e->angleDelta().y(), e->angleDelta().x());
+            QWheelEvent hwe(e->pos(), e->globalPos(), pixelDelta, angleDelta, e->delta(),
+                            Qt::Horizontal, e->buttons(), e->modifiers(), e->phase());
+            if (e->spontaneous())
+                qt_sendSpontaneousEvent(d->hbar, &hwe);
+            else
+                QApplication::sendEvent(d->hbar, &hwe);
+            e->setAccepted(hwe.isAccepted());
+        } else {
+            QApplication::sendEvent(d->vbar, e);
+        }
+    } else {
+        QApplication::sendEvent(d->hbar, e);
+    }
+}
+#endif // QT_NO_WHEELEVENT
+
 /*!
   \reimp
 */
@@ -1846,8 +1877,17 @@ void QCommonListViewBase::updateHorizontalScrollBar(const QSize &step)
     const bool bothScrollBarsAuto = qq->verticalScrollBarPolicy() == Qt::ScrollBarAsNeeded &&
                                     qq->horizontalScrollBarPolicy() == Qt::ScrollBarAsNeeded;
 
-    if (bothScrollBarsAuto && contentsSize.width() - qq->verticalScrollBar()->width() <= viewport()->width()
-                           && contentsSize.height() - qq->horizontalScrollBar()->height() <= viewport()->height()) {
+    const QSize viewportSize(viewport()->width() + (qq->verticalScrollBar()->maximum() > 0 ? qq->verticalScrollBar()->width() : 0),
+                             viewport()->height() + (qq->horizontalScrollBar()->maximum() > 0 ? qq->horizontalScrollBar()->height() : 0));
+
+    bool verticalWantsToShow = contentsSize.height() > viewportSize.height();
+    bool horizontalWantsToShow;
+    if (verticalWantsToShow)
+        horizontalWantsToShow = contentsSize.width() > viewportSize.width() - qq->verticalScrollBar()->width();
+    else
+        horizontalWantsToShow = contentsSize.width() > viewportSize.width();
+
+    if (bothScrollBarsAuto && !horizontalWantsToShow) {
         // break the infinite loop described above by setting the range to 0, 0.
         // QAbstractScrollArea will then hide the scroll bar for us
         horizontalScrollBar()->setRange(0, 0);
@@ -1868,8 +1908,17 @@ void QCommonListViewBase::updateVerticalScrollBar(const QSize &step)
     const bool bothScrollBarsAuto = qq->verticalScrollBarPolicy() == Qt::ScrollBarAsNeeded &&
                                     qq->horizontalScrollBarPolicy() == Qt::ScrollBarAsNeeded;
 
-    if (bothScrollBarsAuto && contentsSize.width() - qq->verticalScrollBar()->width() <= viewport()->width()
-                           && contentsSize.height() - qq->horizontalScrollBar()->height() <= viewport()->height()) {
+    const QSize viewportSize(viewport()->width() + (qq->verticalScrollBar()->maximum() > 0 ? qq->verticalScrollBar()->width() : 0),
+                             viewport()->height() + (qq->horizontalScrollBar()->maximum() > 0 ? qq->horizontalScrollBar()->height() : 0));
+
+    bool horizontalWantsToShow = contentsSize.width() > viewportSize.width();
+    bool verticalWantsToShow;
+    if (horizontalWantsToShow)
+        verticalWantsToShow = contentsSize.height() > viewportSize.height() - qq->horizontalScrollBar()->height();
+    else
+        verticalWantsToShow = contentsSize.height() > viewportSize.height();
+
+    if (bothScrollBarsAuto && !verticalWantsToShow) {
         // break the infinite loop described above by setting the range to 0, 0.
         // QAbstractScrollArea will then hide the scroll bar for us
         verticalScrollBar()->setRange(0, 0);