QListWidget: setup connections when changing selection model.

QListWidget uses a set of slots for its selection model that are
connected only at creation time. This patch adds the missing
connections cleanup and setup when a user changes the selection
model.

Task-number: QTBUG-50891
Change-Id: I942bae6c471ea1ae22637d09b96d6fbd422f653f
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

3 files changed, 53 insertions, 4 deletions

diff --git a/src/widgets/itemviews/qlistwidget.cpp b/src/widgets/itemviews/qlistwidget.cpp
index 1f129e483b..434e819d9c 100644
--- a/src/widgets/itemviews/qlistwidget.cpp
+++ b/src/widgets/itemviews/qlistwidget.cpp
@@ -1069,10 +1069,6 @@ void QListWidgetPrivate::setup()
     QObject::connect(q, SIGNAL(entered(QModelIndex)), q, SLOT(_q_emitItemEntered(QModelIndex)));
     QObject::connect(model, SIGNAL(dataChanged(QModelIndex,QModelIndex)),
                      q, SLOT(_q_emitItemChanged(QModelIndex)));
-    QObject::connect(q->selectionModel(), SIGNAL(currentChanged(QModelIndex,QModelIndex)),
-                     q, SLOT(_q_emitCurrentItemChanged(QModelIndex,QModelIndex)));
-    QObject::connect(q->selectionModel(), SIGNAL(selectionChanged(QItemSelection,QItemSelection)),
-                     q, SIGNAL(itemSelectionChanged()));
     QObject::connect(model, SIGNAL(dataChanged(QModelIndex,QModelIndex)),
                      q, SLOT(_q_dataChanged(QModelIndex,QModelIndex)));
     QObject::connect(model, SIGNAL(columnsRemoved(QModelIndex,int,int)), q, SLOT(_q_sort()));
@@ -1355,6 +1351,31 @@ QListWidget::~QListWidget()
 }
 
 /*!
+    \reimp
+*/
+
+void QListWidget::setSelectionModel(QItemSelectionModel *selectionModel)
+{
+    Q_D(QListWidget);
+
+    if (d->selectionModel) {
+        QObject::disconnect(d->selectionModel, SIGNAL(currentChanged(QModelIndex,QModelIndex)),
+                            this, SLOT(_q_emitCurrentItemChanged(QModelIndex,QModelIndex)));
+        QObject::disconnect(d->selectionModel, SIGNAL(selectionChanged(QItemSelection,QItemSelection)),
+                            this, SIGNAL(itemSelectionChanged()));
+    }
+
+    QListView::setSelectionModel(selectionModel);
+
+    if (d->selectionModel) {
+        QObject::connect(d->selectionModel, SIGNAL(currentChanged(QModelIndex,QModelIndex)),
+                         this, SLOT(_q_emitCurrentItemChanged(QModelIndex,QModelIndex)));
+        QObject::connect(d->selectionModel, SIGNAL(selectionChanged(QItemSelection,QItemSelection)),
+                         this, SIGNAL(itemSelectionChanged()));
+    }
+}
+
+/*!
     Returns the item that occupies the given \a row in the list if one has been
     set; otherwise returns 0.
 
diff --git a/src/widgets/itemviews/qlistwidget.h b/src/widgets/itemviews/qlistwidget.h
index ed85dbac5d..06e2469398 100644
--- a/src/widgets/itemviews/qlistwidget.h
+++ b/src/widgets/itemviews/qlistwidget.h
@@ -207,6 +207,8 @@ public:
     explicit QListWidget(QWidget *parent = Q_NULLPTR);
     ~QListWidget();
 
+    void setSelectionModel(QItemSelectionModel *selectionModel) Q_DECL_OVERRIDE;
+
     QListWidgetItem *item(int row) const;
     int row(const QListWidgetItem *item) const;
     void insertItem(int row, QListWidgetItem *item);
diff --git a/tests/auto/widgets/itemviews/qlistwidget/tst_qlistwidget.cpp b/tests/auto/widgets/itemviews/qlistwidget/tst_qlistwidget.cpp
index 84b00147ca..e8bd86bee5 100644
--- a/tests/auto/widgets/itemviews/qlistwidget/tst_qlistwidget.cpp
+++ b/tests/auto/widgets/itemviews/qlistwidget/tst_qlistwidget.cpp
@@ -115,6 +115,7 @@ private slots:
     void QTBUG8086_currentItemChangedOnClick();
     void QTBUG14363_completerWithAnyKeyPressedEditTriggers();
     void mimeData();
+    void QTBUG50891_ensureSelectionModelSignalConnectionsAreSet();
 
 protected slots:
     void rowsAboutToBeInserted(const QModelIndex &parent, int first, int last)
@@ -1700,5 +1701,30 @@ void tst_QListWidget::mimeData()
     delete data2;
 }
 
+void tst_QListWidget::QTBUG50891_ensureSelectionModelSignalConnectionsAreSet()
+{
+    qRegisterMetaType<QListWidgetItem*>("QListWidgetItem*");
+    QListWidget list;
+    for (int i = 0 ; i < 4; ++i)
+        new QListWidgetItem(QString::number(i), &list);
+
+    list.setSelectionModel(new QItemSelectionModel(list.model()));
+    list.show();
+
+    QSignalSpy currentItemChangedSpy(&list, SIGNAL(currentItemChanged(QListWidgetItem*,QListWidgetItem*)));
+    QSignalSpy itemSelectionChangedSpy(&list, SIGNAL(itemSelectionChanged()));
+
+    QVERIFY(QTest::qWaitForWindowExposed(&list));
+
+    QCOMPARE(currentItemChangedSpy.count(), 0);
+    QCOMPARE(itemSelectionChangedSpy.count(), 0);
+
+    QTest::mouseClick(list.viewport(), Qt::LeftButton, 0, list.visualItemRect(list.item(2)).center());
+
+    QCOMPARE(currentItemChangedSpy.count(), 1);
+    QCOMPARE(itemSelectionChangedSpy.count(), 1);
+
+}
+
 QTEST_MAIN(tst_QListWidget)
 #include "tst_qlistwidget.moc"