Merge commit '145023f5'

* commit '145023f5':
  4xm: reject frames not compatible with the declared version

See: c4338237Merged-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/4xm.c

@@ -891,6 +891,9 @@ static int decode_frame(AVCodecContext *avctx, void *data,
                 av_log(f->avctx, AV_LOG_ERROR, "cframe id mismatch %d %d\n",
                        id, avctx->frame_number);
 
+            if (f->version <= 1)
+                return AVERROR_INVALIDDATA;
+
             cfrm->size = cfrm->id = 0;
             frame_4cc  = AV_RL32("pfrm");
         } else