Fix some runtime qml warnings

src/app/qml/ReasonDialog.qml

@@ -31,7 +31,7 @@ Kirigami.Page {
         Keys.onReturnPressed: event => {
             if (event.modifiers & Qt.ControlModifier) {
                 root.accepted(reason.text);
-                root.closeDialog();
+                root.Kirigami.PageStack.closeDialog();
             }
         }
 
@@ -52,14 +52,14 @@ Kirigami.Page {
                 QQC2.DialogButtonBox.buttonRole: QQC2.DialogButtonBox.AcceptRole
                 onClicked: {
                     root.accepted(reason.text);
-                    root.closeDialog();
+                    root.Kirigami.PageStack.closeDialog();
                 }
             }
             QQC2.Button {
                 icon.name: "dialog-cancel-symbolic"
                 text: i18nc("@action", "Cancel")
                 QQC2.DialogButtonBox.buttonRole: QQC2.DialogButtonBox.RejectRole
-                onClicked: root.closeDialog()
+                onClicked: root.Kirigami.PageStack.closeDialog()
             }
         }
     }

src/app/qml/RoomPage.qml

@@ -113,7 +113,7 @@ Kirigami.Page {
             }
         },
         Kirigami.Action {
-            visible: Kirigami.Settings.isMobile || !(root.Kirigami.PageStack.pageStack as Kirigami.PageRow).wideMode
+            visible: Kirigami.Settings.isMobile || !(root.Kirigami.PageStack.pageStack as Kirigami.PageRow)?.wideMode
             icon.name: "view-right-new"
             onTriggered: (root.QQC2.ApplicationWindow.window as Main).openRoomDrawer()
         }
@@ -289,7 +289,7 @@ Kirigami.Page {
 
     footer: Loader {
         id: chatBarLoader
-        height: active ? (item as ChatBar).implicitHeight : 0
+        height: active ? (item as ChatBar)?.implicitHeight : 0
         active: timelineViewLoader.active && !root.currentRoom.readOnly
         sourceComponent: ChatBar {
             id: chatBar

src/chatbar/EmojiDialog.qml

@@ -65,7 +65,7 @@ QQC2.Popup {
     padding: 2
 
     implicitHeight: Kirigami.Units.gridUnit * 20 + 2 * padding
-    width: Math.min(contentItem.categoryIconSize * 11 + 2 * padding, QQC2.ApplicationWindow.window.width)
+    width: Math.min(contentItem.categoryIconSize * 11 + 2 * padding, QQC2.ApplicationWindow.window?.width)
     contentItem: EmojiPicker {
         id: emojiPicker
         height: 400

src/rooms/ExploreComponent.qml

@@ -55,7 +55,7 @@ RowLayout {
     QQC2.ToolButton {
         id: menuButton
 
-        property QQC2.Menu menuItem: undefined
+        property QQC2.Menu menuItem: null
 
         function openMenu(): void {
             if (!menuItem || !menuItem.visible) {
@@ -69,7 +69,7 @@ RowLayout {
 
         Accessible.role: Accessible.ButtonMenu
         display: QQC2.AbstractButton.IconOnly
-        down: pressed || menuItem.visible
+        down: pressed || menuItem?.visible
         text: i18nc("@action:button", "Show Menu")
         icon.name: "application-menu-symbolic"
 
@@ -78,7 +78,7 @@ RowLayout {
         Keys.onEnterPressed: openMenu()
         Accessible.onPressAction: openMenu()
 
-        QQC2.ToolTip.visible: hovered && !menuItem.visible
+        QQC2.ToolTip.visible: hovered && !menuItem?.visible
         QQC2.ToolTip.text: text
         QQC2.ToolTip.delay: Kirigami.Units.toolTipDelay
     }