Avoid possible crash in Context::Applet::collapse

BUG: 258741
FIXED-IN: 2.4.2

ChangeLog

@@ -24,6 +24,8 @@ VERSION 2.4.2-Beta 1
       reduce the number of cache-related crashes.
 
   BUGFIXES:
+    * Avoid crash in ContextView when accessing Plasma::Applet::view().
+      (BR 258741)
     * Fixed playlist tooltip getting too tall for multiline comments. (BR 256038)
     * Made equalizer keywords (dB,kHz,...) translatable. (BR 263572)
     * Made equalizer preset names translatable. (BR 263596)

src/context/Applet.cpp

@@ -311,7 +311,11 @@ Context::Applet::collapse( bool on )
     connect( pan, SIGNAL(finished()), SLOT(collapseAnimationFinished()) );
     m_animation = pan;
     pan->setDirection( QAbstractAnimation::Forward );
+
     ContextView *v = static_cast<ContextView*>( view() );
+    // Plasma::Applet::view() might return 0, if the widget is not yet constructed, etc.
+    // \sa https://bugs.kde.org/show_bug.cgi?id=258741
+    DEBUG_ASSERT(v, return)
     v->addCollapseAnimation( pan );
 }