Toplevel::windowRole becomes virtual and is copied to Deleted

Toplevel::windowRole accesses WinInfo unconditionally causing crashes
if we have a Toplevel subclass which doesn't use WinInfo. So let's
make it virtual and copy to Deleted.

deleted.cpp

@@ -81,6 +81,7 @@ void Deleted::copyToDeleted(Toplevel* c)
     m_frame = c->frameId();
     m_opacity = c->opacity();
     m_type = c->windowType(true);
+    m_windowRole = c->windowRole();
     if (WinInfo* cinfo = dynamic_cast< WinInfo* >(info))
         cinfo->disable();
     Client* client = dynamic_cast<Client*>(c);
@@ -189,6 +190,11 @@ double Deleted::opacity() const
     return m_opacity;
 }
 
+QByteArray Deleted::windowRole() const
+{
+    return m_windowRole;
+}
+
 } // namespace
 
 #include "deleted.moc"

deleted.h

@@ -72,6 +72,7 @@ public:
         return m_wasClient;
     }
     double opacity() const override;
+    QByteArray windowRole() const override;
 
     const Decoration::Renderer *decorationRenderer() const {
         return m_decorationRenderer;
@@ -106,6 +107,7 @@ private:
     Decoration::Renderer *m_decorationRenderer;
     double m_opacity;
     NET::WindowType m_type = NET::Unknown;
+    QByteArray m_windowRole;
 };
 
 inline void Deleted::refWindow()

toplevel.cpp

@@ -470,6 +470,11 @@ void Toplevel::addDamage(const QRegion &damage)
     }
 }
 
+QByteArray Toplevel::windowRole() const
+{
+    return QByteArray(info->windowRole());
+}
+
 } // namespace
 
 #include "toplevel.moc"

toplevel.h

@@ -254,7 +254,7 @@ public:
     bool isOnAllDesktops() const;
     bool isOnAllActivities() const;
 
-    QByteArray windowRole() const;
+    virtual QByteArray windowRole() const;
     QByteArray sessionId() const;
     QByteArray resourceName() const;
     QByteArray resourceClass() const;
@@ -709,11 +709,6 @@ inline QByteArray Toplevel::resourceClass() const
     return resource_class; // it is always lowercase
 }
 
-inline QByteArray Toplevel::windowRole() const
-{
-    return QByteArray(info->windowRole());
-}
-
 inline bool Toplevel::unredirected() const
 {
     return unredirect;