Fix moving of TreeView items

Property binding for row property in styleData causes an update which
tries to read new value for the index property, but index is changed
afterwards which causes old value to be read. This may lead to crashes
and other unwanted behavior.

Depth changes are now delivered to update item depths in visible
items and model index changes though role instead of looking for a row
change.

Task-number: QTBUG-47523
Change-Id: I540cd06a25281f18e4628f4b030cf969dc8e0a7f
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

2 files changed, 52 insertions, 1 deletions

diff --git a/tests/auto/qquicktreemodeladaptor/tst_qquicktreemodeladaptor.cpp b/tests/auto/qquicktreemodeladaptor/tst_qquicktreemodeladaptor.cpp
index 13a92ea7..34c8f7cc 100644
--- a/tests/auto/qquicktreemodeladaptor/tst_qquicktreemodeladaptor.cpp
+++ b/tests/auto/qquicktreemodeladaptor/tst_qquicktreemodeladaptor.cpp
@@ -81,6 +81,7 @@ private slots:
 
     void moveRows_data();
     void moveRows();
+    void reparentOnSameRow();
 
     void selectionForRowRange();
 
@@ -1160,6 +1161,56 @@ void tst_QQuickTreeModelAdaptor::moveRows()
     compareModels(tma, model);
 }
 
+void tst_QQuickTreeModelAdaptor::reparentOnSameRow()
+{
+    TestModel model(2, 1);
+    model.alternateChildlessRows = false;
+    QQuickTreeModelAdaptor tma;
+    tma.setModel(&model);
+
+    const QModelIndex &destParent = model.index(0, 0);
+    const QModelIndex &sourceParent = QModelIndex();
+    QVERIFY(destParent.isValid());
+    tma.expand(destParent);
+    QVERIFY(tma.isExpanded(destParent));
+
+    QSignalSpy dataChangedSpy(&tma, SIGNAL(dataChanged(QModelIndex,QModelIndex,QVector<int>)));
+    QSignalSpy rowsMovedSpy(&tma, SIGNAL(rowsMoved(QModelIndex,int,int,QModelIndex,int)));
+    QVERIFY(rowsMovedSpy.isValid());
+    QVERIFY(dataChangedSpy.isValid());
+
+    QVERIFY(model.moveRows(sourceParent, 1, 1, destParent, 2));
+
+    QModelIndex movedIndex = tma.index(3, 0, QModelIndex());
+    QVERIFY(movedIndex.isValid());
+    QCOMPARE(movedIndex.data(QQuickTreeModelAdaptor::DepthRole).toInt(), 1);
+    QCOMPARE(tma.data(movedIndex, QQuickTreeModelAdaptor::ModelIndexRole).toModelIndex(), model.index(2, 0, destParent));
+
+    // at least DepthRole and ModeIndexRole changes should have happened for the affected row
+    bool depthChanged = false;
+    bool modelIndexChanged = false;
+    QList<QList<QVariant> > &changes = dataChangedSpy;
+    foreach (QList<QVariant> change, changes) {
+        if (change.at(0) == movedIndex) {
+            if (change.at(2).value<QVector<int> >().contains(QQuickTreeModelAdaptor::DepthRole))
+                depthChanged = true;
+            if (change.at(2).value<QVector<int> >().contains(QQuickTreeModelAdaptor::ModelIndexRole))
+                modelIndexChanged = true;
+        }
+    }
+
+    QCOMPARE(depthChanged, true);
+    QCOMPARE(modelIndexChanged, true);
+
+    QCOMPARE(rowsMovedSpy.count(), 0);
+
+    model.moveRow(destParent, 2, QModelIndex(), 1);
+
+    QCOMPARE(rowsMovedSpy.count(), 0);
+    QVERIFY(tma.testConsistency());
+    compareModels(tma, model);
+}
+
 void tst_QQuickTreeModelAdaptor::selectionForRowRange()
 {
     const int ModelRowCount = 9;
diff --git a/tests/auto/shared/testmodel.h b/tests/auto/shared/testmodel.h
index 00e74129..d1f49a4d 100644
--- a/tests/auto/shared/testmodel.h
+++ b/tests/auto/shared/testmodel.h
@@ -238,7 +238,7 @@ public:
     bool moveRows(const QModelIndex &sourceParent, int sourceRow, int count, const QModelIndex &destinationParent, int destinationChild)
     {
         Q_ASSERT_X(sourceRow >= 0 && sourceRow < rowCount(sourceParent)
-                   && count > 0 && sourceRow + count < rowCount(sourceParent)
+                   && count > 0 && sourceRow + count - 1 < rowCount(sourceParent)
                    && destinationChild >= 0 && destinationChild <= rowCount(destinationParent),
                    Q_FUNC_INFO, "Rows out of range.");
         Q_ASSERT_X(!(sourceParent == destinationParent && destinationChild >= sourceRow && destinationChild < sourceRow + count),