libwebp: update to v0.5.1

third_party/libwebp/dec/webp.c

 // Copyright 2010 Google Inc. All Rights Reserved.
 //
 // Use of this source code is governed by a BSD-style license
 // that can be found in the COPYING 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.
 // -----------------------------------------------------------------------------
 //
 // Main decoding functions for WEBP images.
@@ skipping 385 matching lines @@
   if (headers != NULL) {
     *headers = hdrs;
     headers->offset = data - headers->data;
     assert((uint64_t)(data - headers->data) < MAX_CHUNK_PAYLOAD);
     assert(headers->offset == headers->data_size - data_size);
   }
   return VP8_STATUS_OK;  // Return features from VP8 header.
 }
 
 VP8StatusCode WebPParseHeaders(WebPHeaderStructure* const headers) {
-  VP8StatusCode status;
+  // status is marked volatile as a workaround for a clang-3.8 (aarch64) bug
+  volatile VP8StatusCode status;
   int has_animation = 0;
   assert(headers != NULL);
   // fill out headers, ignore width/height/has_alpha.
   status = ParseHeadersInternal(headers->data, headers->data_size,
                                 NULL, NULL, NULL, &has_animation,
                                 NULL, headers);
   if (status == VP8_STATUS_OK || status == VP8_STATUS_NOT_ENOUGH_DATA) {
     // TODO(jzern): full support of animation frames will require API additions.
     if (has_animation) {
       status = VP8_STATUS_UNSUPPORTED_FEATURE;
@@ skipping 76 matching lines @@
         if (!VP8LDecodeImage(dec)) {
           status = dec->status_;
         }
       }
     }
     VP8LDelete(dec);
   }
 
   if (status != VP8_STATUS_OK) {
     WebPFreeDecBuffer(params->output);
-  }
-
-  if (params->options != NULL && params->options->flip) {
-    status = WebPFlipBuffer(params->output);
+  } else {
+    if (params->options != NULL && params->options->flip) {
+      // This restores the original stride values if options->flip was used
+      // during the call to WebPAllocateDecBuffer above.
+      status = WebPFlipBuffer(params->output);
+    }
   }
   return status;
 }
 
 // Helpers
 static uint8_t* DecodeIntoRGBABuffer(WEBP_CSP_MODE colorspace,
                                      const uint8_t* const data,
                                      size_t data_size,
                                      uint8_t* const rgba,
                                      int stride, size_t size) {
@@ skipping 222 matching lines @@
 
   status = GetFeatures(data, data_size, &config->input);
   if (status != VP8_STATUS_OK) {
     if (status == VP8_STATUS_NOT_ENOUGH_DATA) {
       return VP8_STATUS_BITSTREAM_ERROR;  // Not-enough-data treated as error.
     }
     return status;
   }
 
   WebPResetDecParams(&params);
+  params.options = &config->options;
   params.output = &config->output;
-  params.options = &config->options;
-  status = DecodeInto(data, data_size, &params);
+  if (WebPAvoidSlowMemory(params.output, &config->input)) {
+    // decoding to slow memory: use a temporary in-mem buffer to decode into.
+    WebPDecBuffer in_mem_buffer;
+    WebPInitDecBuffer(&in_mem_buffer);
+    in_mem_buffer.colorspace = config->output.colorspace;
+    in_mem_buffer.width = config->input.width;
+    in_mem_buffer.height = config->input.height;
+    params.output = &in_mem_buffer;
+    status = DecodeInto(data, data_size, &params);
+    if (status == VP8_STATUS_OK) {  // do the slow-copy
+      status = WebPCopyDecBufferPixels(&in_mem_buffer, &config->output);
+    }
+    WebPFreeDecBuffer(&in_mem_buffer);
+  } else {
+    status = DecodeInto(data, data_size, &params);
+  }
 
   return status;
 }
 
 //------------------------------------------------------------------------------
 // Cropping and rescaling.
 
 int WebPIoInitFromOptions(const WebPDecoderOptions* const options,
                           VP8Io* const io, WEBP_CSP_MODE src_colorspace) {
   const int W = io->width;
@@ skipping 28 matching lines @@
     int scaled_width = options->scaled_width;
     int scaled_height = options->scaled_height;
     if (!WebPRescalerGetScaledDimensions(w, h, &scaled_width, &scaled_height)) {
       return 0;
     }
     io->scaled_width = scaled_width;
     io->scaled_height = scaled_height;
   }
 
   // Filter
-  io->bypass_filtering = options && options->bypass_filtering;
+  io->bypass_filtering = (options != NULL) && options->bypass_filtering;
 
   // Fancy upsampler
 #ifdef FANCY_UPSAMPLING
   io->fancy_upsampling = (options == NULL) || (!options->no_fancy_upsampling);
 #endif
 
   if (io->use_scaling) {
     // disable filter (only for large downscaling ratio).
     io->bypass_filtering = (io->scaled_width < W * 3 / 4) &&
                            (io->scaled_height < H * 3 / 4);
     io->fancy_upsampling = 0;
   }
   return 1;
 }
 
 //------------------------------------------------------------------------------
-