Take account of spanned items in QTreeView when dragging.

Also remove some code which has been unused since it was introduced in
32182d107fa75e5619ecc91a81f50626f429ebe1

Task-number: QTBUG-25140
Change-Id: Ic7053d68d8200f845c1ae330342d27af7275e057
Reviewed-by: Tarja Sundqvist <tarja.sundqvist@digia.com>
Reviewed-by: David Faure <faure@kde.org>

src/widgets/itemviews/qtreeview.cpp

@@ -1343,39 +1343,16 @@ void QTreeViewPrivate::_q_modelDestroyed()
 QItemViewPaintPairs QTreeViewPrivate::draggablePaintPairs(const QModelIndexList &indexes, QRect *r) const
 {
     Q_ASSERT(r);
-    return QAbstractItemViewPrivate::draggablePaintPairs(indexes, r);
     Q_Q(const QTreeView);
-    QRect &rect = *r;
-    const QRect viewportRect = viewport->rect();
-    int itemOffset = 0;
-    int row = firstVisibleItem(&itemOffset);
-    QPair<int, int> startEnd = startAndEndColumns(viewportRect);
-    QVector<int> columns;
-    for (int i = startEnd.first; i <= startEnd.second; ++i) {
-        int logical = header->logicalIndex(i);
-        if (!header->isSectionHidden(logical))
-            columns += logical;
+    if (spanningIndexes.isEmpty())
+        return QAbstractItemViewPrivate::draggablePaintPairs(indexes, r);
+    QModelIndexList list;
+    foreach (const QModelIndex &idx, indexes) {
+        if (idx.column() > 0 && q->isFirstColumnSpanned(idx.row(), idx.parent()))
+            continue;
+        list << idx;
     }
-    QSet<QModelIndex> visibleIndexes;
-    for (; itemOffset < viewportRect.bottom() && row < viewItems.count(); ++row) {
-        const QModelIndex &index = viewItems.at(row).index;
-        for (int colIndex = 0; colIndex < columns.count(); ++colIndex)
-            visibleIndexes += index.sibling(index.row(), columns.at(colIndex));
-        itemOffset += itemHeight(row);
-    }
-
-    //now that we have the visible indexes, we can try to find those which are selected
-    QItemViewPaintPairs ret;
-    for (int i = 0; i < indexes.count(); ++i) {
-        const QModelIndex &index = indexes.at(i);
-        if (visibleIndexes.contains(index)) {
-            const QRect current = q->visualRect(index);
-            ret += qMakePair(current, index);
-            rect |= current;
-        }
-    }
-    rect &= viewportRect;
-    return ret;
+    return QAbstractItemViewPrivate::draggablePaintPairs(list, r);
 }
 
 void QTreeViewPrivate::adjustViewOptionsForIndex(QStyleOptionViewItemV4 *option, const QModelIndex &current) const

tests/auto/widgets/itemviews/qtreeview/tst_qtreeview.cpp

@@ -210,6 +210,8 @@ private slots:
     void indexRowSizeHint();
     void addRowsWhileSectionsAreHidden();
     void filterProxyModelCrash();
+    void renderToPixmap_data();
+    void renderToPixmap();
     void styleOptionViewItem();
     void keyboardNavigationWithDisabled();
 
@@ -2890,6 +2892,37 @@ void tst_QTreeView::filterProxyModelCrash()
     view.repaint(); //used to crash
 }
 
+void tst_QTreeView::renderToPixmap_data()
+{
+    QTest::addColumn<int>("row");
+    QTest::newRow("row-0") << 0;
+    QTest::newRow("row-1") << 1;
+}
+
+void tst_QTreeView::renderToPixmap()
+{
+    QFETCH(int, row);
+    PublicView view;
+    QStandardItemModel model;
+
+    model.appendRow(new QStandardItem("Spanning"));
+    model.appendRow(QList<QStandardItem*>() << new QStandardItem("Not") << new QStandardItem("Spanning"));
+
+    view.setModel(&model);
+    view.setFirstColumnSpanned(0, QModelIndex(), true);
+
+#ifdef QT_BUILD_INTERNAL
+    {
+        // We select the index at row=0 because it spans the
+        // column (regression test for an assert)
+        // We select the index at row=1 for coverage.
+        QItemSelection sel(model.index(row,0), model.index(row,1));
+        QRect rect;
+        view.aiv_priv()->renderToPixmap(sel.indexes(), &rect);
+    }
+#endif
+}
+
 void tst_QTreeView::styleOptionViewItem()
 {
     class MyDelegate : public QStyledItemDelegate