Refactor PNGImageDecoder's call to setSize

third_party/WebKit/Source/platform/image-decoders/png/PNGImageDecoder.cpp

 /*
  * Copyright (C) 2006 Apple Computer, Inc.
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  *
  * Portions are Copyright (C) 2001 mozilla.org
  *
  * Other contributors:
  *   Stuart Parmenter <stuart@mozilla.com>
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 176 matching lines @@
     return nullptr;
 
   SkColorSpaceTransferFn fn;
   fn.fG = 1.0f / pngFixedToFloat(inverseGamma);
   fn.fA = 1.0f;
   fn.fB = fn.fC = fn.fD = fn.fE = fn.fF = 0.0f;
 
   return SkColorSpace::MakeRGB(fn, toXYZD50);
 }
 
+void PNGImageDecoder::setColorSpace() {
+  if (ignoresColorSpace())
+    return;
+  png_structp png = m_reader->pngPtr();
+  png_infop info = m_reader->infoPtr();
+  const int colorType = png_get_color_type(png, info);
+  if (!(colorType & PNG_COLOR_MASK_COLOR))
+    return;
+  // We only support color profiles for color PALETTE and RGB[A] PNG.
+  // TODO(msarett): Add GRAY profile support, block CYMK?
+  sk_sp<SkColorSpace> colorSpace = readColorSpace(png, info);
+  if (colorSpace)
+    setEmbeddedColorSpace(colorSpace);
+}
+
+bool PNGImageDecoder::setSize(unsigned width, unsigned height) {
+  DCHECK(!isDecodedSizeAvailable());
+  // Protect against large PNGs. See http://bugzil.la/251381 for more details.
+  const unsigned long maxPNGSize = 1000000UL;
+  if (width > maxPNGSize || height > maxPNGSize)
+    return false;
+  return ImageDecoder::setSize(width, height);

[Peter Kasting, 2017/03/22 21:59:52]

Nit: Or:

  return (width <= maxPNGSize) && (height <= maxPNGSize) &&
         ImageDecoder::setSize(width, height);

[scroggo_chromium, 2017/03/23 12:24:41]

Done.

+}
+
 void PNGImageDecoder::headerAvailable() {
+  DCHECK(isDecodedSizeAvailable());
+
   png_structp png = m_reader->pngPtr();
   png_infop info = m_reader->infoPtr();
 
   png_uint_32 width, height;
   int bitDepth, colorType, interlaceType, compressionType;
   png_get_IHDR(png, info, &width, &height, &bitDepth, &colorType,
                &interlaceType, &compressionType, nullptr);
 
   // The options we set here match what Mozilla does.
 
   // Expand to ensure we use 24-bit for RGB and 32-bit for RGBA.
   if (colorType == PNG_COLOR_TYPE_PALETTE ||
       (colorType == PNG_COLOR_TYPE_GRAY && bitDepth < 8))
     png_set_expand(png);
 
   if (png_get_valid(png, info, PNG_INFO_tRNS))
     png_set_expand(png);
 
   if (bitDepth == 16)
     png_set_strip_16(png);
 
   if (colorType == PNG_COLOR_TYPE_GRAY ||
       colorType == PNG_COLOR_TYPE_GRAY_ALPHA)
     png_set_gray_to_rgb(png);
 
-  // Only set the size and the color space of the image once since non-first
-  // frames also use this method: there is no per-frame color space, and the
-  // image size is determined from the header width and height.
-  if (!isDecodedSizeAvailable()) {
-    // Protect against large PNGs. See http://bugzil.la/251381 for more details.
-    const unsigned long maxPNGSize = 1000000UL;
-    if (width > maxPNGSize || height > maxPNGSize) {
-      longjmp(JMPBUF(png), 1);
-      return;
-    }
-
-    // Set the image size now that the image header is available.
-    if (!setSize(width, height)) {
-      longjmp(JMPBUF(png), 1);
-      return;
-    }
-
-    if ((colorType & PNG_COLOR_MASK_COLOR) && !ignoresColorSpace()) {
-      // We only support color profiles for color PALETTE and RGB[A] PNG.
-      // TODO(msarret): Add GRAY profile support, block CYMK?
-      if (sk_sp<SkColorSpace> colorSpace = readColorSpace(png, info))
-        setEmbeddedColorSpace(colorSpace);
-    }
-  }
-
   if (!hasEmbeddedColorSpace()) {
     const double inverseGamma = 0.45455;
     const double defaultGamma = 2.2;
     double gamma;
     if (!ignoresColorSpace() && png_get_gAMA(png, info, &gamma)) {
       const double maxGamma = 21474.83;
       if ((gamma <= 0.0) || (gamma > maxGamma)) {
         gamma = inverseGamma;
         png_set_gAMA(png, info, gamma);
       }
       png_set_gamma(png, defaultGamma, gamma);
     } else {
       png_set_gamma(png, defaultGamma, inverseGamma);
     }
   }
 
-  DCHECK(isDecodedSizeAvailable());
-
   // Tell libpng to send us rows for interlaced pngs.
   if (interlaceType == PNG_INTERLACE_ADAM7)
     png_set_interlace_handling(png);
 
   // Update our info now (so we can get color channel info).
   png_read_update_info(png, info);
 
   int channels = png_get_channels(png, info);
   DCHECK(channels == 3 || channels == 4);
   m_hasAlphaChannel = (channels == 4);
@@ skipping 208 matching lines @@
   return m_reader->frameIsReceivedAtIndex(index);
 }
 
 float PNGImageDecoder::frameDurationAtIndex(size_t index) const {
   if (index < m_frameBufferCache.size())
     return m_frameBufferCache[index].duration();
   return 0;
 }
 
 }  // namespace blink