forward port SVN commit 1013841 by woebbe:

Also use the name of the attachment to determine the mime type if a silly, broken 
client only gives you application/octet-stream as content type.

CCMAIL: woebbeking@kde.org

svn path=/trunk/KDE/kdepim/; revision=1013857

kmreaderwin.cpp

@@ -2443,7 +2443,7 @@ void KMReaderWin::openAttachment( int id, const QString & name )
   if ( KMail::Util::handleUrlOnMac( mAtmCurrentName ) )
     return;
 
-  if ( mimetype.isNull() ) {
+  if ( mimetype.isNull() || mimetype->name() == "application/octet-stream" ) {
     // consider the filename if mimetype can not be found by content-type
     mimetype = KMimeType::findByPath( name, 0, true /* no disk access */ );
   }