never show the dialog on destroy()

the remove action is now hooked to another slot, askDestroy()
it *MAY* solve the "Do you wish to remove this default desktop" bug, or may get it worse
CCBUG:332137

src/plasma/applet.cpp

@@ -255,20 +255,6 @@ void Applet::destroy()
         return; //don't double delete
     }
 
-    if (isContainment()) {
-        QMessageBox *box = new QMessageBox(QMessageBox::Warning, i18nc("@title:window %1 is the name of the containment", "Remove %1", title()), i18nc("%1 is the name of the containment", "Do you really want to remove this %1?", title()), QMessageBox::StandardButtons( QMessageBox::Yes | QMessageBox::No ));
-        box->setWindowFlags((Qt::WindowFlags)(box->windowFlags() | Qt::WA_DeleteOnClose));
-        box->open();
-
-        connect(box->button(QMessageBox::Yes), &QAbstractButton::clicked,
-            [=] () {
-                d->transient = true;
-                d->cleanUpAndDelete();
-            });
-
-        return;
-    }
-
     d->transient = true;
     //FIXME: an animation on leave if !isContainment() would be good again .. which should be handled by the containment class
     d->cleanUpAndDelete();
@@ -480,7 +466,7 @@ void Applet::flushPendingConstraintsEvents()
         if (closeApplet) {
             closeApplet->setEnabled(unlocked);
             closeApplet->setVisible(unlocked);
-            connect(closeApplet, SIGNAL(triggered(bool)), this, SLOT(destroy()), Qt::UniqueConnection);
+            connect(closeApplet, SIGNAL(triggered(bool)), this, SLOT(askDestroy()), Qt::UniqueConnection);
         }
 
         QAction *configAction = d->actions->action("configure");

src/plasma/applet.h

@@ -589,6 +589,7 @@ class PLASMA_EXPORT Applet : public QObject
         Applet(const QString &packagePath, uint appletId);
 
         Q_PRIVATE_SLOT(d, void cleanUpAndDelete())
+        Q_PRIVATE_SLOT(d, void askDestroy())
         Q_PRIVATE_SLOT(d, void updateShortcuts())
         Q_PRIVATE_SLOT(d, void globalShortcutChanged())
         Q_PRIVATE_SLOT(d, void propagateConfigChanged())

src/plasma/private/applet_p.cpp

@@ -29,6 +29,7 @@
 #include <qstandardpaths.h>
 
 #include <QDebug>
+#include <QMessageBox>
 #include <kiconloader.h>
 #include <klocalizedstring.h>
 #include <kkeysequencewidget.h>
@@ -180,6 +181,30 @@ void AppletPrivate::showConfigurationRequiredMessage(bool show, const QString &r
     Q_UNUSED(reason)
 }
 
+void AppletPrivate::askDestroy()
+{
+    if (q->immutability() != Types::Mutable || transient || !started) {
+        return; //don't double delete
+    }
+
+    if (q->isContainment()) {
+        QMessageBox *box = new QMessageBox(QMessageBox::Warning, i18nc("@title:window %1 is the name of the containment", "Remove %1", q->title()), i18nc("%1 is the name of the containment", "Do you really want to remove this %1?", q->title()), QMessageBox::StandardButtons( QMessageBox::Yes | QMessageBox::No ));
+        box->setWindowFlags((Qt::WindowFlags)(box->windowFlags() | Qt::WA_DeleteOnClose));
+        box->open();
+
+        QObject::connect(box->button(QMessageBox::Yes), &QAbstractButton::clicked,
+            [=] () {
+                transient = true;
+                cleanUpAndDelete();
+            });
+
+        return;
+    }
+
+    transient = true;
+    cleanUpAndDelete();
+}
+
 void AppletPrivate::globalShortcutChanged()
 {
     if (!activationAction) {

src/plasma/private/applet_p.h

@@ -50,6 +50,7 @@ public:
 
     // the interface
     virtual void showConfigurationRequiredMessage(bool show, const QString &reason);
+    void askDestroy();
     virtual void cleanUpAndDelete();
 
     // put all setup routines for script here. at this point we can assume that