FolderListModel: pessimize change signals when the filter changes

FileInfoThread doesn't have separate signals for insertions, deletions
and updates, so QQuickFolderListModel shouldn't make an assumption
that if the list got bigger, an insertion was the only thing that
happened.

Task-number: QTBUG-36576
Change-Id: Ibb02d64e1645dd6df231d28a93e424aaad0effff
Reviewed-by: Alan Alpert <aalpert@blackberry.com>

3 files changed, 38 insertions, 11 deletions

diff --git a/tests/auto/qml/qquickfolderlistmodel/data/resetfiltering/test1.html b/tests/auto/qml/qquickfolderlistmodel/data/resetfiltering/test1.html
new file mode 100644
index 0000000000..4da4639310
--- /dev/null
+++ b/tests/auto/qml/qquickfolderlistmodel/data/resetfiltering/test1.html
@@ -0,0 +1 @@
+<P>This file contains some HTML.</P>
diff --git a/tests/auto/qml/qquickfolderlistmodel/data/resetfiltering/test2.html b/tests/auto/qml/qquickfolderlistmodel/data/resetfiltering/test2.html
new file mode 100644
index 0000000000..4da4639310
--- /dev/null
+++ b/tests/auto/qml/qquickfolderlistmodel/data/resetfiltering/test2.html
@@ -0,0 +1 @@
+<P>This file contains some HTML.</P>
diff --git a/tests/auto/qml/qquickfolderlistmodel/tst_qquickfolderlistmodel.cpp b/tests/auto/qml/qquickfolderlistmodel/tst_qquickfolderlistmodel.cpp
index a6e6345223..4296ae4f09 100644
--- a/tests/auto/qml/qquickfolderlistmodel/tst_qquickfolderlistmodel.cpp
+++ b/tests/auto/qml/qquickfolderlistmodel/tst_qquickfolderlistmodel.cpp
@@ -73,6 +73,7 @@ private slots:
     void basicProperties();
     void showFiles();
     void resetFiltering();
+    void nameFilters();
     void refresh();
     void cdUp();
 #ifdef Q_OS_WIN32
@@ -169,26 +170,50 @@ void tst_qquickfolderlistmodel::resetFiltering()
     QAbstractListModel *flm = qobject_cast<QAbstractListModel*>(component.create());
     QVERIFY(flm != 0);
 
+    flm->setProperty("folder", testFileUrl("resetfiltering"));
+    // _q_directoryUpdated may be triggered if model was empty before, but there won't be a rowsRemoved signal
+    QTRY_COMPARE(flm->property("count").toInt(),3); // all files visible
+
+    flm->setProperty("folder", testFileUrl("resetfiltering/innerdir"));
+    // _q_directoryChanged is triggered so it's a total model refresh
+    QTRY_COMPARE(flm->property("count").toInt(),1); // should just be "test2.txt" visible
+
+    flm->setProperty("folder", testFileUrl("resetfiltering"));
+    // _q_directoryChanged is triggered so it's a total model refresh
+    QTRY_COMPARE(flm->property("count").toInt(),3); // all files visible
+}
+
+void tst_qquickfolderlistmodel::nameFilters()
+{
+    // see QTBUG-36576
+    QQmlComponent component(&engine, testFileUrl("resetFiltering.qml"));
+    checkNoErrors(component);
+
+    QAbstractListModel *flm = qobject_cast<QAbstractListModel*>(component.create());
+    QVERIFY(flm != 0);
+
     connect(flm, SIGNAL(rowsRemoved(QModelIndex,int,int)),
             this, SLOT(removed(QModelIndex,int,int)));
 
+    QTRY_VERIFY(flm->rowCount() > 0);
     flm->setProperty("folder", testFileUrl("resetfiltering"));
-    QTRY_COMPARE(flm->property("count").toInt(),1); // should just be "test.txt" visible
+    QTRY_COMPARE(flm->property("count").toInt(),3); // all files visible
+
     int count = flm->rowCount();
+    flm->setProperty("nameFilters", QStringList() << "*.txt");
+    // _q_directoryUpdated triggered with range 0:1
+    QTRY_COMPARE(flm->property("count").toInt(),1);
+    QCOMPARE(flm->data(flm->index(0),FileNameRole), QVariant("test.txt"));
     QCOMPARE(removeStart, 0);
     QCOMPARE(removeEnd, count-1);
 
-    flm->setProperty("folder", testFileUrl("resetfiltering/innerdir"));
-    QTRY_COMPARE(flm->property("count").toInt(),1); // should just be "test2.txt" visible
-    count = flm->rowCount();
-    QCOMPARE(removeStart, 0);
-    QCOMPARE(removeEnd, count-1);
+    flm->setProperty("nameFilters", QStringList() << "*.html");
+    QTRY_COMPARE(flm->property("count").toInt(),2);
+    QCOMPARE(flm->data(flm->index(0),FileNameRole), QVariant("test1.html"));
+    QCOMPARE(flm->data(flm->index(1),FileNameRole), QVariant("test2.html"));
 
-    flm->setProperty("folder", testFileUrl("resetfiltering"));
-    QTRY_COMPARE(flm->property("count").toInt(),1); // should just be "test.txt" visible
-    count = flm->rowCount();
-    QCOMPARE(removeStart, 0);
-    QCOMPARE(removeEnd, count-1);
+    flm->setProperty("nameFilters", QStringList());
+    QTRY_COMPARE(flm->property("count").toInt(),3); // all files visible
 }
 
 void tst_qquickfolderlistmodel::refresh()