avformat/mvdec: check for EOF

Fixes #6805.
Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavformat/mvdec.c

@@ -227,7 +227,9 @@ static int read_table(AVFormatContext *avctx, AVStream *st,
                        int (*parse)(AVFormatContext *avctx, AVStream *st,
                                     const char *name, int size))
 {
-    int count, i;
+    unsigned count;
+    int i;
+
     AVIOContext *pb = avctx->pb;
     avio_skip(pb, 4);
     count = avio_rb32(pb);
@@ -235,6 +237,10 @@ static int read_table(AVFormatContext *avctx, AVStream *st,
     for (i = 0; i < count; i++) {
         char name[17];
         int size;
+
+        if (avio_feof(pb))
+            return AVERROR_EOF;
+
         avio_read(pb, name, 16);
         name[sizeof(name) - 1] = 0;
         size = avio_rb32(pb);