Report repetition count in SkCodec

third_party/gif/SkGifImageReader.h

 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  *
  * The contents of this file are subject to the Mozilla Public License Version
  * 1.1 (the "License"); you may not use this file except in compliance with
  * the License. You may obtain a copy of the License at
  * http://www.mozilla.org/MPL/
  *
  * Software distributed under the License is distributed on an "AS IS" basis,
@@ skipping 280 matching lines @@
         , m_screenWidth(0)
         , m_screenHeight(0)
         , m_loopCount(cLoopCountNotSeen)
         , m_streamBuffer(stream)
         , m_parseCompleted(false)
         , m_firstFrameHasAlpha(false)
         , m_firstFrameSupportsIndex8(false)
     {
     }
 
-    static constexpr int cLoopCountNotSeen = -2;
-
     ~SkGifImageReader()
     {
     }
 
     void setClient(SkGifCodec* client) { m_client = client; }
 
     unsigned screenWidth() const { return m_screenWidth; }
     unsigned screenHeight() const { return m_screenHeight; }
 
     // Option to pass to parse(). All enums are negative, because a non-negative value is used to
     // indicate that the Reader should parse up to and including the frame indicated.
     enum SkGIFParseQuery {
         // Parse enough to determine the size. Note that this parses the first frame's header,
         // since we may decide to expand based on the frame's dimensions.
         SkGIFSizeQuery        = -1,
         // Parse to the end, so we know about all frames.
         SkGIFFrameCountQuery  = -2,
+        // Parse until we see the loop count.
+        SkGIFLoopCountQuery   = -3,
     };
 
     // Parse incoming GIF data stream into internal data structures.
     // Non-negative values are used to indicate to parse through that frame.
     // Return true if parsing has progressed or there is not enough data.
     // Return false if a fatal error is encountered.
     bool parse(SkGIFParseQuery);
 
     // Decode the frame indicated by frameIndex.
     // frameComplete will be set to true if the frame is completely decoded.
     // The method returns false if there is an error.
     bool decode(size_t frameIndex, bool* frameComplete);
 
     size_t imagesCount() const
     {
         if (m_frames.empty())
             return 0;
 
         // This avoids counting an empty frame when the file is truncated right after
         // SkGIFControlExtension but before SkGIFImageHeader.
         // FIXME: This extra complexity is not necessary and we should just report m_frames.size().
         return m_frames.back()->isHeaderDefined() ? m_frames.size() : m_frames.size() - 1;
     }
-    int loopCount() const { return m_loopCount; }
+    int loopCount() const {
+        if (cLoopCountNotSeen == m_loopCount) {
+            return 0;
+        }
+        return m_loopCount;
+    }
 
     const SkGIFColorMap& globalColorMap() const
     {
         return m_globalColorMap;
     }
 
     const SkGIFFrameContext* frameContext(size_t index) const
     {
         return index < m_frames.size() ? m_frames[index].get() : 0;
     }
@@ skipping 28 matching lines @@
 
     // Parsing state machine.
     SkGIFState m_state; // Current decoder master state.
     size_t m_bytesToConsume; // Number of bytes to consume for next stage of parsing.
 
     // Global (multi-image) state.
     int m_version; // Either 89 for GIF89 or 87 for GIF87.
     unsigned m_screenWidth; // Logical screen width & height.
     unsigned m_screenHeight;
     SkGIFColorMap m_globalColorMap;
+
+    static constexpr int cLoopCountNotSeen = -2;
     int m_loopCount; // Netscape specific extension block to control the number of animation loops a GIF renders.
 
     std::vector<std::unique_ptr<SkGIFFrameContext>> m_frames;
 
     SkStreamBuffer m_streamBuffer;
     bool m_parseCompleted;
 
     // These values can be computed before we create a SkGIFFrameContext, so we
     // store them here instead of on m_frames[0].
     bool m_firstFrameHasAlpha;
     bool m_firstFrameSupportsIndex8;
 };
 
 #endif