ps.c: add a safety net to this while loop.

modules/demux/ps.c

@@ -249,8 +249,9 @@ static void FindLength( demux_t *p_demux )
         i_size = stream_Size( p_demux->s );
         i_end = __MAX( 0, __MIN( 200000, i_size ) );
         stream_Seek( p_demux->s, i_size - i_end );
+        i = 0;
 
-        while( vlc_object_alive (p_demux) && Demux2( p_demux, true ) > 0 );
+        while( vlc_object_alive (p_demux) && i < 40 && Demux2( p_demux, true ) > 0 );
         if( i_current_pos >= 0 ) stream_Seek( p_demux->s, i_current_pos );
     }