demux: mp4: don't parse data if trun is missing (cid #1219918)

modules/demux/mp4/mp4.c

@@ -5318,8 +5318,6 @@ static int LeafParseMDATwithMOOF( demux_t *p_demux, MP4_Box_t *p_moof )
                 }
             }
 
-        }
-
             const MP4_Box_data_trun_t *p_trun_data = p_track->context.BOXDATA(p_trun);
 
            /* NOW PARSE TRUN WITH MDAT */
@@ -5330,6 +5328,8 @@ static int LeafParseMDATwithMOOF( demux_t *p_demux, MP4_Box_t *p_moof )
                 goto end;
 
             p_track->context.p_trun = p_track->context.p_trun->p_next;
+        }
+
         if ( p_sys->context.i_mdatbytesleft == 0 )
             p_sys->context.i_current_box_type = 0;
         return VLC_SUCCESS;