libvpx: Pull from upstream

source/libvpx/vpxstats.c

 /*
  *  Copyright (c) 2013 The WebM project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 23 matching lines @@
     stats->file = fdopen(fd, "rb");
     fstat(fd, &stat_buf);
     stats->buf.sz = stat_buf.st_size;
     stats->buf.buf = mmap(NULL, stats->buf.sz, PROT_READ, MAP_PRIVATE, fd, 0);
     res = (stats->buf.buf != NULL);
 #else
     size_t nbytes;
 
     stats->file = fopen(fpf, "rb");
 
+    if (stats->file == NULL)
+      fatal("First-pass stats file does not exist!");
+
     if (fseek(stats->file, 0, SEEK_END))
       fatal("First-pass stats file must be seekable!");
 
     stats->buf.sz = stats->buf_alloc_sz = ftell(stats->file);
     rewind(stats->file);
 
     stats->buf.buf = malloc(stats->buf_alloc_sz);
 
     if (!stats->buf.buf)
       fatal("Failed to allocate first-pass stats buffer (%lu bytes)",
@@ skipping 59 matching lines @@
 
     memcpy(stats->buf_ptr, pkt, len);
     stats->buf.sz += len;
     stats->buf_ptr += len;
   }
 }
 
 vpx_fixed_buf_t stats_get(stats_io_t *stats) {
   return stats->buf;
 }