QColumnView: don't set an invalid index as the current one

When any item in a QColumnView gets selected, the next column gets
normally set to show the children of that index. When we are on a leaf
of a tree model, the next column will have an invalid root index, yet
we set that root index as the "current index" for the current column.

Due to the special handling for invalid indexes in
QAbstractItemView::setCurrentIndex, this ends up breaking the current
item AND the current selection in that column. Further clicks inside
the column for instance trigger the entire column (up to the clicked
index) to get selected, because of that broken first setCurrentIndex.

The simple fix is to stop doing that when the next column has
an invalid root index.

Task-number: QTBUG-2329
Change-Id: Icd10c0b958e25cd868536e1315561787977b68bd
Reviewed-by: David Faure <david.faure@kdab.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/src/widgets/itemviews/qcolumnview.cpp b/src/widgets/itemviews/qcolumnview.cpp
index 1c60d50922..3234e1e832 100644
--- a/src/widgets/itemviews/qcolumnview.cpp
+++ b/src/widgets/itemviews/qcolumnview.cpp
@@ -976,8 +976,11 @@ void QColumnViewPrivate::_q_changeCurrentColumn()
             QAbstractItemView *view = columns.at(i);
             view->setSelectionModel(replacementSelectionModel);
             view->setFocusPolicy(Qt::NoFocus);
-            if (columns.size() > i + 1)
-                view->setCurrentIndex(columns.at(i+1)->rootIndex());
+            if (columns.size() > i + 1) {
+                const QModelIndex newRootIndex = columns.at(i + 1)->rootIndex();
+                if (newRootIndex.isValid())
+                    view->setCurrentIndex(newRootIndex);
+            }
             break;
         }
     }