QmlDesigner: Suppress some warnings from the assets library

Change-Id: Idd192ce20e610a1689cfc9b0a11215dd16f09911
Reviewed-by: Samuel Ghinet <samuel.ghinet@qt.io>
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>

share/qtcreator/qmldesigner/itemLibraryQmlSources/Assets.qml

@@ -42,7 +42,7 @@ Item {
         enabled: true
         anchors.fill: parent
 
-        onEntered: {
+        onEntered: (drag)=> {
             files = []
             for (var i = 0; i < drag.urls.length; ++i) {
                 var url = drag.urls[i].toString();
@@ -179,7 +179,7 @@ Item {
                         onExited: tooltipBackend.hideTooltip()
                         onCanceled: tooltipBackend.hideTooltip()
                         onPositionChanged: tooltipBackend.reposition()
-                        onPressed: {
+                        onPressed: (mouse)=> {
                             forceActiveFocus()
                             if (mouse.button === Qt.LeftButton) {
                                 var ctrlDown = mouse.modifiers & Qt.ControlModifier
@@ -200,7 +200,7 @@ Item {
                             }
                         }
 
-                        onReleased: {
+                        onReleased: (mouse)=> {
                             if (mouse.button === Qt.LeftButton) {
                                 if (!(mouse.modifiers & Qt.ControlModifier))
                                     selectedAssets = {}

src/plugins/qmldesigner/components/itemlibrary/itemlibraryassetsmodel.cpp

@@ -138,9 +138,8 @@ QVariant ItemLibraryAssetsModel::data(const QModelIndex &index, int role) const
         return {};
     }
 
-    if (m_assetsDir && m_roleNames.contains(role)) {
-        return m_assetsDir->property(m_roleNames.value(role));
-    }
+    if (m_roleNames.contains(role))
+        return m_assetsDir ? m_assetsDir->property(m_roleNames.value(role)) : QVariant();
 
     qWarning() << Q_FUNC_INFO << "Invalid role requested: " << QString::number(role);
     return {};