Fix issue with stale Fragment from previous popup

Author: tchrapovic

gui/admin-gui/src/main/java/com/evolveum/midpoint/gui/api/page/PageBase.java

@@ -522,8 +522,12 @@ public void showMainPopup(Popupable popupable, AjaxRequestTarget target) {
         dialog.setContent(popupable.getContent());
         dialog.setFooter(popupable.getFooter());
 
-        if (popupable.getTitleComponent() != null) {
-            dialog.setTitleComponent(popupable.getTitleComponent());
+        Component titleComponent = popupable.getTitleComponent();
+        if (titleComponent != null) {
+            dialog.setTitleComponent(titleComponent);
+        } else {
+            // Reset to default title component so we don't keep stale Fragment from previous popup
+            dialog.setTitleComponent(dialog.createDefaultTitleComponent());
         }
 
         dialog.setTitle(popupable.getTitle());

gui/admin-gui/src/main/java/com/evolveum/midpoint/web/component/dialog/MainPopupDialog.java

@@ -136,6 +136,12 @@ public void setTitleComponent(@NotNull Component titleComponent) {
         getDialogComponent().addOrReplace(titleComponent);
     }
 
+    public Component createDefaultTitleComponent() {
+        Label titleLabel = new Label("title", () -> title != null ? title.getObject() : null);
+        titleLabel.add(new VisibleBehaviour(this::isTitleVisible));
+        return titleLabel;
+    }
+
     @Override
     protected WebMarkupContainer newDialog(String dialogId) {
         return new MidpointForm<>(dialogId);