Ensure layout is updated when section property changes.

When the section property changed the sections were recalculated,
but the items were not relayouted.
Also avoid 'Unable to assign undefined value' warning by setting
section item parent before component is completed.

Change-Id: I7bd8eb369877a6faf72b32b80b45a68366c95772
Task-number: QTBUG-17759
Reviewed-by: Michael Brasser

2 files changed, 24 insertions, 1 deletions

diff --git a/tests/auto/declarative/qdeclarativelistview/data/listview-sections_delegate.qml b/tests/auto/declarative/qdeclarativelistview/data/listview-sections_delegate.qml
index 9d9cda8..b2d9213 100644
--- a/tests/auto/declarative/qdeclarativelistview/data/listview-sections_delegate.qml
+++ b/tests/auto/declarative/qdeclarativelistview/data/listview-sections_delegate.qml
@@ -1,6 +1,7 @@
 import QtQuick 1.0
 
 Rectangle {
+    property string sectionProperty: "number"
     width: 240
     height: 320
     color: "#ffffff"
@@ -56,7 +57,7 @@ Rectangle {
         height: 320
         model: testModel
         delegate: myDelegate
-        section.property: "number"
+        section.property: sectionProperty
         section.delegate: Rectangle {
             objectName: "sect_" + section
             color: "#99bb99"
diff --git a/tests/auto/declarative/qdeclarativelistview/tst_qdeclarativelistview.cpp b/tests/auto/declarative/qdeclarativelistview/tst_qdeclarativelistview.cpp
index c7f90da..e8b6028 100644
--- a/tests/auto/declarative/qdeclarativelistview/tst_qdeclarativelistview.cpp
+++ b/tests/auto/declarative/qdeclarativelistview/tst_qdeclarativelistview.cpp
@@ -1091,6 +1091,28 @@ void tst_QDeclarativeListView::sectionsDelegate()
     QList<QDeclarativeItem*> items = findItems<QDeclarativeItem>(contentItem, "sect_1");
     QCOMPARE(items.count(), 1);
 
+    // QTBUG-17759
+    model.modifyItem(0, "One", "aaa");
+    model.modifyItem(1, "One", "aaa");
+    model.modifyItem(2, "One", "aaa");
+    model.modifyItem(3, "Four", "aaa");
+    model.modifyItem(4, "Four", "aaa");
+    model.modifyItem(5, "Four", "aaa");
+    model.modifyItem(6, "Five", "aaa");
+    model.modifyItem(7, "Five", "aaa");
+    model.modifyItem(8, "Five", "aaa");
+    model.modifyItem(9, "Two", "aaa");
+    model.modifyItem(10, "Two", "aaa");
+    model.modifyItem(11, "Two", "aaa");
+    QTest::qWait(100);
+    canvas->rootObject()->setProperty("sectionProperty", "name");
+    for (int i = 0; i < 4; ++i) {
+        QDeclarativeItem *item = findItem<QDeclarativeItem>(contentItem,
+                "sect_" + model.name(i*3));
+        QVERIFY(item);
+        QTRY_COMPARE(item->y(), qreal(i*20*4));
+    }
+
     delete canvas;
 }