From 61cb884d79679342f26c1fa619b5a09c9fdc4aa1 Mon Sep 17 00:00:00 2001
From: James Zern <jzern@google.com>
Date: Tue, 12 Nov 2013 21:46:17 -0800
Subject: [PATCH] demux: (non-exp) fail if the fragmented flag is set

otherwise make sure that all frames are marked as a fragment. there's
still some work to do with validation if fragments are expected to cover
the entire canvas.

Change-Id: Id59e95ac01b9340ba8c6039b0c3b65484b91c42f
---
 src/demux/demux.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/demux/demux.c b/src/demux/demux.c
index cd039573..a3affff4 100644
--- a/src/demux/demux.c
+++ b/src/demux/demux.c
@@ -603,6 +603,8 @@ static int IsValidSimpleFormat(const WebPDemuxer* const dmux) {
 
 // If 'exact' is true, check that the image resolution matches the canvas.
 // If 'exact' is false, check that the x/y offsets do not exceed the canvas.
+// TODO(jzern): this is insufficient in the fragmented image case if the
+// expectation is that the fragments completely cover the canvas.
 static int CheckFrameBounds(const Frame* const frame, int exact,
                             int canvas_width, int canvas_height) {
   if (exact) {
@@ -630,6 +632,9 @@ static int IsValidExtendedFormat(const WebPDemuxer* const dmux) {
   if (dmux->canvas_width_ <= 0 || dmux->canvas_height_ <= 0) return 0;
   if (dmux->loop_count_ < 0) return 0;
   if (dmux->state_ == WEBP_DEMUX_DONE && dmux->frames_ == NULL) return 0;
+#ifndef WEBP_EXPERIMENTAL_FEATURES
+  if (has_fragments) return 0;
+#endif
 
   while (f != NULL) {
     const int cur_frame_set = f->frame_num_;
@@ -641,8 +646,10 @@ static int IsValidExtendedFormat(const WebPDemuxer* const dmux) {
       const ChunkData* const image = f->img_components_;
       const ChunkData* const alpha = f->img_components_ + 1;
 
+      if (has_fragments && !f->is_fragment_) return 0;
       if (!has_fragments && f->is_fragment_) return 0;
       if (!has_frames && f->frame_num_ > 1) return 0;
+
       if (f->complete_) {
         if (alpha->size_ == 0 && image->size_ == 0) return 0;
         // Ensure alpha precedes image bitstream.