Fixed crashed in kmail/kontact when trying to print a message.

The problem was introduced by #25.
This resolves #27.

Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>

kmail/kmreaderwin.cpp

@@ -436,6 +436,7 @@ KMReaderWin::KMReaderWin(TQWidget *aParent,
     mHeaderOnlyAttachmentsAction( 0 ),
     mSelectEncodingAction( 0 ),
     mToggleFixFontAction( 0 ),
+    mToggleMimePartTreeAction( 0 ),
     mCanStartDrag( false ),
     mHtmlWriter( 0 ),
     mSavedRelativePosition( 0 ),
@@ -1461,7 +1462,8 @@ void KMReaderWin::showHideMimeTree( bool isPlainTextTopLevel ) {
     saveSplitterSizes( reader );
     mMimePartTree->hide();
   }
-  if ( mToggleMimePartTreeAction->isChecked() != mMimePartTree->isVisible() ) {
+  // mToggleMimePartTreeAction is null in case the reader win was created without an actionCollection
+  if ( mToggleMimePartTreeAction && mToggleMimePartTreeAction->isChecked() != mMimePartTree->isVisible() ) {
     mToggleMimePartTreeAction->setChecked( mMimePartTree->isVisible() );
   }
 }