Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1035 insertions, 0 deletions

diff --git a/image/decoders/nsPNGDecoder.cpp b/image/decoders/nsPNGDecoder.cpp
new file mode 100644
index 0000000000..afc2762515
--- /dev/null
+++ b/image/decoders/nsPNGDecoder.cpp
@@ -0,0 +1,1035 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ImageLogging.h"  // Must appear first
+#include "nsPNGDecoder.h"
+
+#include <algorithm>
+#include <cstdint>
+
+#include "gfxColor.h"
+#include "gfxPlatform.h"
+#include "imgFrame.h"
+#include "nsColor.h"
+#include "nsRect.h"
+#include "nspr.h"
+#include "png.h"
+
+#include "RasterImage.h"
+#include "SurfaceCache.h"
+#include "SurfacePipeFactory.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/Telemetry.h"
+
+using namespace mozilla::gfx;
+
+using std::min;
+
+namespace mozilla {
+namespace image {
+
+static LazyLogModule sPNGLog("PNGDecoder");
+static LazyLogModule sPNGDecoderAccountingLog("PNGDecoderAccounting");
+
+// limit image dimensions (bug #251381, #591822, #967656, and #1283961)
+#ifndef MOZ_PNG_MAX_WIDTH
+#  define MOZ_PNG_MAX_WIDTH 0x7fffffff  // Unlimited
+#endif
+#ifndef MOZ_PNG_MAX_HEIGHT
+#  define MOZ_PNG_MAX_HEIGHT 0x7fffffff  // Unlimited
+#endif
+
+/* Controls the maximum chunk size configuration for libpng. We set this to a
+ * very large number, 256MB specifically. */
+static constexpr png_alloc_size_t kPngMaxChunkSize = 0x10000000;
+
+nsPNGDecoder::AnimFrameInfo::AnimFrameInfo()
+    : mDispose(DisposalMethod::KEEP), mBlend(BlendMethod::OVER), mTimeout(0) {}
+
+#ifdef PNG_APNG_SUPPORTED
+
+int32_t GetNextFrameDelay(png_structp aPNG, png_infop aInfo) {
+  // Delay, in seconds, is delayNum / delayDen.
+  png_uint_16 delayNum = png_get_next_frame_delay_num(aPNG, aInfo);
+  png_uint_16 delayDen = png_get_next_frame_delay_den(aPNG, aInfo);
+
+  if (delayNum == 0) {
+    return 0;  // SetFrameTimeout() will set to a minimum.
+  }
+
+  if (delayDen == 0) {
+    delayDen = 100;  // So says the APNG spec.
+  }
+
+  // Need to cast delay_num to float to have a proper division and
+  // the result to int to avoid a compiler warning.
+  return static_cast<int32_t>(static_cast<double>(delayNum) * 1000 / delayDen);
+}
+
+nsPNGDecoder::AnimFrameInfo::AnimFrameInfo(png_structp aPNG, png_infop aInfo)
+    : mDispose(DisposalMethod::KEEP), mBlend(BlendMethod::OVER), mTimeout(0) {
+  png_byte dispose_op = png_get_next_frame_dispose_op(aPNG, aInfo);
+  png_byte blend_op = png_get_next_frame_blend_op(aPNG, aInfo);
+
+  if (dispose_op == PNG_DISPOSE_OP_PREVIOUS) {
+    mDispose = DisposalMethod::RESTORE_PREVIOUS;
+  } else if (dispose_op == PNG_DISPOSE_OP_BACKGROUND) {
+    mDispose = DisposalMethod::CLEAR;
+  } else {
+    mDispose = DisposalMethod::KEEP;
+  }
+
+  if (blend_op == PNG_BLEND_OP_SOURCE) {
+    mBlend = BlendMethod::SOURCE;
+  } else {
+    mBlend = BlendMethod::OVER;
+  }
+
+  mTimeout = GetNextFrameDelay(aPNG, aInfo);
+}
+#endif
+
+// First 8 bytes of a PNG file
+const uint8_t nsPNGDecoder::pngSignatureBytes[] = {137, 80, 78, 71,
+                                                   13,  10, 26, 10};
+
+nsPNGDecoder::nsPNGDecoder(RasterImage* aImage)
+    : Decoder(aImage),
+      mLexer(Transition::ToUnbuffered(State::FINISHED_PNG_DATA, State::PNG_DATA,
+                                      SIZE_MAX),
+             Transition::TerminateSuccess()),
+      mNextTransition(Transition::ContinueUnbuffered(State::PNG_DATA)),
+      mLastChunkLength(0),
+      mPNG(nullptr),
+      mInfo(nullptr),
+      mCMSLine(nullptr),
+      interlacebuf(nullptr),
+      mFormat(SurfaceFormat::UNKNOWN),
+      mChannels(0),
+      mPass(0),
+      mFrameIsHidden(false),
+      mDisablePremultipliedAlpha(false),
+      mGotInfoCallback(false),
+      mUsePipeTransform(false),
+      mNumFrames(0) {}
+
+nsPNGDecoder::~nsPNGDecoder() {
+  if (mPNG) {
+    png_destroy_read_struct(&mPNG, mInfo ? &mInfo : nullptr, nullptr);
+  }
+  if (mCMSLine) {
+    free(mCMSLine);
+  }
+  if (interlacebuf) {
+    free(interlacebuf);
+  }
+}
+
+nsPNGDecoder::TransparencyType nsPNGDecoder::GetTransparencyType(
+    const OrientedIntRect& aFrameRect) {
+  // Check if the image has a transparent color in its palette.
+  if (HasAlphaChannel()) {
+    return TransparencyType::eAlpha;
+  }
+  if (!aFrameRect.IsEqualEdges(FullFrame())) {
+    MOZ_ASSERT(HasAnimation());
+    return TransparencyType::eFrameRect;
+  }
+
+  return TransparencyType::eNone;
+}
+
+void nsPNGDecoder::PostHasTransparencyIfNeeded(
+    TransparencyType aTransparencyType) {
+  switch (aTransparencyType) {
+    case TransparencyType::eNone:
+      return;
+
+    case TransparencyType::eAlpha:
+      PostHasTransparency();
+      return;
+
+    case TransparencyType::eFrameRect:
+      // If the first frame of animated image doesn't draw into the whole image,
+      // then record that it is transparent. For subsequent frames, this doesn't
+      // affect transparency, because they're composited on top of all previous
+      // frames.
+      if (mNumFrames == 0) {
+        PostHasTransparency();
+      }
+      return;
+  }
+}
+
+// CreateFrame() is used for both simple and animated images.
+nsresult nsPNGDecoder::CreateFrame(const FrameInfo& aFrameInfo) {
+  MOZ_ASSERT(HasSize());
+  MOZ_ASSERT(!IsMetadataDecode());
+
+  // Check if we have transparency, and send notifications if needed.
+  auto transparency = GetTransparencyType(aFrameInfo.mFrameRect);
+  PostHasTransparencyIfNeeded(transparency);
+  mFormat = transparency == TransparencyType::eNone ? SurfaceFormat::OS_RGBX
+                                                    : SurfaceFormat::OS_RGBA;
+
+  // Make sure there's no animation or padding if we're downscaling.
+  MOZ_ASSERT_IF(Size() != OutputSize(), mNumFrames == 0);
+  MOZ_ASSERT_IF(Size() != OutputSize(), !GetImageMetadata().HasAnimation());
+  MOZ_ASSERT_IF(Size() != OutputSize(),
+                transparency != TransparencyType::eFrameRect);
+
+  Maybe<AnimationParams> animParams;
+#ifdef PNG_APNG_SUPPORTED
+  if (!IsFirstFrameDecode() && png_get_valid(mPNG, mInfo, PNG_INFO_acTL)) {
+    mAnimInfo = AnimFrameInfo(mPNG, mInfo);
+
+    if (mAnimInfo.mDispose == DisposalMethod::CLEAR) {
+      // We may have to display the background under this image during
+      // animation playback, so we regard it as transparent.
+      PostHasTransparency();
+    }
+
+    animParams.emplace(
+        AnimationParams{aFrameInfo.mFrameRect.ToUnknownRect(),
+                        FrameTimeout::FromRawMilliseconds(mAnimInfo.mTimeout),
+                        mNumFrames, mAnimInfo.mBlend, mAnimInfo.mDispose});
+  }
+#endif
+
+  // If this image is interlaced, we can display better quality intermediate
+  // results to the user by post processing them with ADAM7InterpolatingFilter.
+  SurfacePipeFlags pipeFlags = aFrameInfo.mIsInterlaced
+                                   ? SurfacePipeFlags::ADAM7_INTERPOLATE
+                                   : SurfacePipeFlags();
+
+  if (mNumFrames == 0) {
+    // The first frame may be displayed progressively.
+    pipeFlags |= SurfacePipeFlags::PROGRESSIVE_DISPLAY;
+  }
+
+  SurfaceFormat inFormat;
+  if (mTransform && !mUsePipeTransform) {
+    // QCMS will output in the correct format.
+    inFormat = mFormat;
+  } else if (transparency == TransparencyType::eAlpha) {
+    // We are outputting directly as RGBA, so we need to swap at this step.
+    inFormat = SurfaceFormat::R8G8B8A8;
+  } else {
+    // We have no alpha channel, so we need to unpack from RGB to BGRA.
+    inFormat = SurfaceFormat::R8G8B8;
+  }
+
+  // Only apply premultiplication if the frame has true alpha. If we ever
+  // support downscaling animated images, we will need to premultiply for frame
+  // rect transparency when downscaling as well.
+  if (transparency == TransparencyType::eAlpha && !mDisablePremultipliedAlpha) {
+    pipeFlags |= SurfacePipeFlags::PREMULTIPLY_ALPHA;
+  }
+
+  qcms_transform* pipeTransform = mUsePipeTransform ? mTransform : nullptr;
+  Maybe<SurfacePipe> pipe = SurfacePipeFactory::CreateSurfacePipe(
+      this, Size(), OutputSize(), aFrameInfo.mFrameRect, inFormat, mFormat,
+      animParams, pipeTransform, pipeFlags);
+
+  if (!pipe) {
+    mPipe = SurfacePipe();
+    return NS_ERROR_FAILURE;
+  }
+
+  mPipe = std::move(*pipe);
+
+  mFrameRect = aFrameInfo.mFrameRect;
+  mPass = 0;
+
+  MOZ_LOG(sPNGDecoderAccountingLog, LogLevel::Debug,
+          ("PNGDecoderAccounting: nsPNGDecoder::CreateFrame -- created "
+           "image frame with %dx%d pixels for decoder %p",
+           mFrameRect.Width(), mFrameRect.Height(), this));
+
+  return NS_OK;
+}
+
+// set timeout and frame disposal method for the current frame
+void nsPNGDecoder::EndImageFrame() {
+  if (mFrameIsHidden) {
+    return;
+  }
+
+  mNumFrames++;
+
+  Opacity opacity = mFormat == SurfaceFormat::OS_RGBX
+                        ? Opacity::FULLY_OPAQUE
+                        : Opacity::SOME_TRANSPARENCY;
+
+  PostFrameStop(opacity);
+}
+
+nsresult nsPNGDecoder::InitInternal() {
+  mDisablePremultipliedAlpha =
+      bool(GetSurfaceFlags() & SurfaceFlags::NO_PREMULTIPLY_ALPHA);
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+  static png_byte color_chunks[] = {99,  72, 82, 77, '\0',     // cHRM
+                                    105, 67, 67, 80, '\0'};    // iCCP
+  static png_byte unused_chunks[] = {98,  75, 71, 68,  '\0',   // bKGD
+                                     101, 88, 73, 102, '\0',   // eXIf
+                                     104, 73, 83, 84,  '\0',   // hIST
+                                     105, 84, 88, 116, '\0',   // iTXt
+                                     111, 70, 70, 115, '\0',   // oFFs
+                                     112, 67, 65, 76,  '\0',   // pCAL
+                                     115, 67, 65, 76,  '\0',   // sCAL
+                                     112, 72, 89, 115, '\0',   // pHYs
+                                     115, 66, 73, 84,  '\0',   // sBIT
+                                     115, 80, 76, 84,  '\0',   // sPLT
+                                     116, 69, 88, 116, '\0',   // tEXt
+                                     116, 73, 77, 69,  '\0',   // tIME
+                                     122, 84, 88, 116, '\0'};  // zTXt
+#endif
+
+  // Initialize the container's source image header
+  // Always decode to 24 bit pixdepth
+
+  mPNG = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr,
+                                nsPNGDecoder::error_callback,
+                                nsPNGDecoder::warning_callback);
+  if (!mPNG) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  mInfo = png_create_info_struct(mPNG);
+  if (!mInfo) {
+    png_destroy_read_struct(&mPNG, nullptr, nullptr);
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+  // Ignore unused chunks
+  if (mCMSMode == CMSMode::Off || IsMetadataDecode()) {
+    png_set_keep_unknown_chunks(mPNG, 1, color_chunks, 2);
+  }
+
+  png_set_keep_unknown_chunks(mPNG, 1, unused_chunks,
+                              (int)sizeof(unused_chunks) / 5);
+#endif
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+  png_set_user_limits(mPNG, MOZ_PNG_MAX_WIDTH, MOZ_PNG_MAX_HEIGHT);
+  png_set_chunk_malloc_max(mPNG, kPngMaxChunkSize);
+#endif
+
+#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+  // Disallow palette-index checking, for speed; we would ignore the warning
+  // anyhow.  This feature was added at libpng version 1.5.10 and is disabled
+  // in the embedded libpng but enabled by default in the system libpng.  This
+  // call also disables it in the system libpng, for decoding speed.
+  // Bug #745202.
+  png_set_check_for_invalid_index(mPNG, 0);
+#endif
+
+#ifdef PNG_SET_OPTION_SUPPORTED
+#  if defined(PNG_sRGB_PROFILE_CHECKS) && PNG_sRGB_PROFILE_CHECKS >= 0
+  // Skip checking of sRGB ICC profiles
+  png_set_option(mPNG, PNG_SKIP_sRGB_CHECK_PROFILE, PNG_OPTION_ON);
+#  endif
+
+#  ifdef PNG_MAXIMUM_INFLATE_WINDOW
+  // Force a larger zlib inflate window as some images in the wild have
+  // incorrectly set metadata (specifically CMF bits) which prevent us from
+  // decoding them otherwise.
+  png_set_option(mPNG, PNG_MAXIMUM_INFLATE_WINDOW, PNG_OPTION_ON);
+#  endif
+#endif
+
+  // use this as libpng "progressive pointer" (retrieve in callbacks)
+  png_set_progressive_read_fn(
+      mPNG, static_cast<png_voidp>(this), nsPNGDecoder::info_callback,
+      nsPNGDecoder::row_callback, nsPNGDecoder::end_callback);
+
+  return NS_OK;
+}
+
+LexerResult nsPNGDecoder::DoDecode(SourceBufferIterator& aIterator,
+                                   IResumable* aOnResume) {
+  MOZ_ASSERT(!HasError(), "Shouldn't call DoDecode after error!");
+
+  return mLexer.Lex(aIterator, aOnResume,
+                    [=](State aState, const char* aData, size_t aLength) {
+                      switch (aState) {
+                        case State::PNG_DATA:
+                          return ReadPNGData(aData, aLength);
+                        case State::FINISHED_PNG_DATA:
+                          return FinishedPNGData();
+                      }
+                      MOZ_CRASH("Unknown State");
+                    });
+}
+
+LexerTransition<nsPNGDecoder::State> nsPNGDecoder::ReadPNGData(
+    const char* aData, size_t aLength) {
+  // If we were waiting until after returning from a yield to call
+  // CreateFrame(), call it now.
+  if (mNextFrameInfo) {
+    if (NS_FAILED(CreateFrame(*mNextFrameInfo))) {
+      return Transition::TerminateFailure();
+    }
+
+    MOZ_ASSERT(mImageData, "Should have a buffer now");
+    mNextFrameInfo = Nothing();
+  }
+
+  // libpng uses setjmp/longjmp for error handling.
+  if (setjmp(png_jmpbuf(mPNG))) {
+    return Transition::TerminateFailure();
+  }
+
+  // Pass the data off to libpng.
+  mLastChunkLength = aLength;
+  mNextTransition = Transition::ContinueUnbuffered(State::PNG_DATA);
+  png_process_data(mPNG, mInfo,
+                   reinterpret_cast<unsigned char*>(const_cast<char*>((aData))),
+                   aLength);
+
+  // Make sure that we've reached a terminal state if decoding is done.
+  MOZ_ASSERT_IF(GetDecodeDone(), mNextTransition.NextStateIsTerminal());
+  MOZ_ASSERT_IF(HasError(), mNextTransition.NextStateIsTerminal());
+
+  // Continue with whatever transition the callback code requested. We
+  // initialized this to Transition::ContinueUnbuffered(State::PNG_DATA) above,
+  // so by default we just continue the unbuffered read.
+  return mNextTransition;
+}
+
+LexerTransition<nsPNGDecoder::State> nsPNGDecoder::FinishedPNGData() {
+  // Since we set up an unbuffered read for SIZE_MAX bytes, if we actually read
+  // all that data something is really wrong.
+  MOZ_ASSERT_UNREACHABLE("Read the entire address space?");
+  return Transition::TerminateFailure();
+}
+
+// Sets up gamma pre-correction in libpng before our callback gets called.
+// We need to do this if we don't end up with a CMS profile.
+static void PNGDoGammaCorrection(png_structp png_ptr, png_infop info_ptr) {
+  double aGamma;
+
+  if (png_get_gAMA(png_ptr, info_ptr, &aGamma)) {
+    if ((aGamma <= 0.0) || (aGamma > 21474.83)) {
+      aGamma = 0.45455;
+      png_set_gAMA(png_ptr, info_ptr, aGamma);
+    }
+    png_set_gamma(png_ptr, 2.2, aGamma);
+  } else {
+    png_set_gamma(png_ptr, 2.2, 0.45455);
+  }
+}
+
+// Adapted from http://www.littlecms.com/pngchrm.c example code
+uint32_t nsPNGDecoder::ReadColorProfile(png_structp png_ptr, png_infop info_ptr,
+                                        int color_type, bool* sRGBTag) {
+  // First try to see if iCCP chunk is present
+  if (png_get_valid(png_ptr, info_ptr, PNG_INFO_iCCP)) {
+    png_uint_32 profileLen;
+    png_bytep profileData;
+    png_charp profileName;
+    int compression;
+
+    png_get_iCCP(png_ptr, info_ptr, &profileName, &compression, &profileData,
+                 &profileLen);
+
+    mInProfile = qcms_profile_from_memory((char*)profileData, profileLen);
+    if (mInProfile) {
+      uint32_t profileSpace = qcms_profile_get_color_space(mInProfile);
+
+      bool mismatch = false;
+      if (color_type & PNG_COLOR_MASK_COLOR) {
+        if (profileSpace != icSigRgbData) {
+          mismatch = true;
+        }
+      } else {
+        if (profileSpace == icSigRgbData) {
+          png_set_gray_to_rgb(png_ptr);
+        } else if (profileSpace != icSigGrayData) {
+          mismatch = true;
+        }
+      }
+
+      if (mismatch) {
+        qcms_profile_release(mInProfile);
+        mInProfile = nullptr;
+      } else {
+        return qcms_profile_get_rendering_intent(mInProfile);
+      }
+    }
+  }
+
+  // Check sRGB chunk
+  if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sRGB)) {
+    *sRGBTag = true;
+
+    int fileIntent;
+    png_set_gray_to_rgb(png_ptr);
+    png_get_sRGB(png_ptr, info_ptr, &fileIntent);
+    uint32_t map[] = {QCMS_INTENT_PERCEPTUAL, QCMS_INTENT_RELATIVE_COLORIMETRIC,
+                      QCMS_INTENT_SATURATION,
+                      QCMS_INTENT_ABSOLUTE_COLORIMETRIC};
+    return map[fileIntent];
+  }
+
+  // Check gAMA/cHRM chunks
+  if (png_get_valid(png_ptr, info_ptr, PNG_INFO_gAMA) &&
+      png_get_valid(png_ptr, info_ptr, PNG_INFO_cHRM)) {
+    qcms_CIE_xyYTRIPLE primaries;
+    qcms_CIE_xyY whitePoint;
+
+    png_get_cHRM(png_ptr, info_ptr, &whitePoint.x, &whitePoint.y,
+                 &primaries.red.x, &primaries.red.y, &primaries.green.x,
+                 &primaries.green.y, &primaries.blue.x, &primaries.blue.y);
+    whitePoint.Y = primaries.red.Y = primaries.green.Y = primaries.blue.Y = 1.0;
+
+    double gammaOfFile;
+
+    png_get_gAMA(png_ptr, info_ptr, &gammaOfFile);
+
+    mInProfile = qcms_profile_create_rgb_with_gamma(whitePoint, primaries,
+                                                    1.0 / gammaOfFile);
+
+    if (mInProfile) {
+      png_set_gray_to_rgb(png_ptr);
+    }
+  }
+
+  return QCMS_INTENT_PERCEPTUAL;  // Our default
+}
+
+void nsPNGDecoder::info_callback(png_structp png_ptr, png_infop info_ptr) {
+  png_uint_32 width, height;
+  int bit_depth, color_type, interlace_type, compression_type, filter_type;
+  unsigned int channels;
+
+  png_bytep trans = nullptr;
+  int num_trans = 0;
+
+  nsPNGDecoder* decoder =
+      static_cast<nsPNGDecoder*>(png_get_progressive_ptr(png_ptr));
+
+  if (decoder->mGotInfoCallback) {
+    MOZ_LOG(sPNGLog, LogLevel::Warning,
+            ("libpng called info_callback more than once\n"));
+    return;
+  }
+
+  decoder->mGotInfoCallback = true;
+
+  // Always decode to 24-bit RGB or 32-bit RGBA
+  png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+               &interlace_type, &compression_type, &filter_type);
+
+  const OrientedIntRect frameRect(0, 0, width, height);
+
+  // Post our size to the superclass
+  decoder->PostSize(frameRect.Width(), frameRect.Height());
+
+  if (width > SurfaceCache::MaximumCapacity() / (bit_depth > 8 ? 16 : 8)) {
+    // libpng needs space to allocate two row buffers
+    png_error(decoder->mPNG, "Image is too wide");
+  }
+
+  if (decoder->HasError()) {
+    // Setting the size led to an error.
+    png_error(decoder->mPNG, "Sizing error");
+  }
+
+  if (color_type == PNG_COLOR_TYPE_PALETTE) {
+    png_set_expand(png_ptr);
+  }
+
+  if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
+    png_set_expand(png_ptr);
+  }
+
+  if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
+    png_color_16p trans_values;
+    png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans, &trans_values);
+    // libpng doesn't reject a tRNS chunk with out-of-range samples
+    // so we check it here to avoid setting up a useless opacity
+    // channel or producing unexpected transparent pixels (bug #428045)
+    if (bit_depth < 16) {
+      png_uint_16 sample_max = (1 << bit_depth) - 1;
+      if ((color_type == PNG_COLOR_TYPE_GRAY &&
+           trans_values->gray > sample_max) ||
+          (color_type == PNG_COLOR_TYPE_RGB &&
+           (trans_values->red > sample_max ||
+            trans_values->green > sample_max ||
+            trans_values->blue > sample_max))) {
+        // clear the tRNS valid flag and release tRNS memory
+        png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
+        num_trans = 0;
+      }
+    }
+    if (num_trans != 0) {
+      png_set_expand(png_ptr);
+    }
+  }
+
+  if (bit_depth == 16) {
+    png_set_scale_16(png_ptr);
+  }
+
+  // We only need to extract the color profile for non-metadata decodes. It is
+  // fairly expensive to read the profile and create the transform so we should
+  // avoid it if not necessary.
+  uint32_t intent = -1;
+  bool sRGBTag = false;
+  if (!decoder->IsMetadataDecode()) {
+    if (decoder->mCMSMode != CMSMode::Off) {
+      intent = gfxPlatform::GetRenderingIntent();
+      uint32_t pIntent =
+          decoder->ReadColorProfile(png_ptr, info_ptr, color_type, &sRGBTag);
+      // If we're not mandating an intent, use the one from the image.
+      if (intent == uint32_t(-1)) {
+        intent = pIntent;
+      }
+    }
+    if (!decoder->mInProfile || !decoder->GetCMSOutputProfile()) {
+      png_set_gray_to_rgb(png_ptr);
+
+      // only do gamma correction if CMS isn't entirely disabled
+      if (decoder->mCMSMode != CMSMode::Off) {
+        PNGDoGammaCorrection(png_ptr, info_ptr);
+      }
+    }
+  }
+
+  // Let libpng expand interlaced images.
+  const bool isInterlaced = interlace_type == PNG_INTERLACE_ADAM7;
+  if (isInterlaced) {
+    png_set_interlace_handling(png_ptr);
+  }
+
+  // now all of those things we set above are used to update various struct
+  // members and whatnot, after which we can get channels, rowbytes, etc.
+  png_read_update_info(png_ptr, info_ptr);
+  decoder->mChannels = channels = png_get_channels(png_ptr, info_ptr);
+
+  //---------------------------------------------------------------//
+  // copy PNG info into imagelib structs (formerly png_set_dims()) //
+  //---------------------------------------------------------------//
+
+  if (channels < 1 || channels > 4) {
+    png_error(decoder->mPNG, "Invalid number of channels");
+  }
+
+#ifdef PNG_APNG_SUPPORTED
+  bool isAnimated = png_get_valid(png_ptr, info_ptr, PNG_INFO_acTL);
+  if (isAnimated) {
+    int32_t rawTimeout = GetNextFrameDelay(png_ptr, info_ptr);
+    decoder->PostIsAnimated(FrameTimeout::FromRawMilliseconds(rawTimeout));
+
+    if (decoder->Size() != decoder->OutputSize() &&
+        !decoder->IsFirstFrameDecode()) {
+      MOZ_ASSERT_UNREACHABLE(
+          "Doing downscale-during-decode "
+          "for an animated image?");
+      png_error(decoder->mPNG, "Invalid downscale attempt");  // Abort decode.
+    }
+  }
+#endif
+
+  auto transparency = decoder->GetTransparencyType(frameRect);
+  if (decoder->IsMetadataDecode()) {
+    // If we are animated then the first frame rect is either:
+    // 1) the whole image if the IDAT chunk is part of the animation
+    // 2) the frame rect of the first fDAT chunk otherwise.
+    // If we are not animated then we want to make sure to call
+    // PostHasTransparency in the metadata decode if we need to. So it's
+    // okay to pass IntRect(0, 0, width, height) here for animated images;
+    // they will call with the proper first frame rect in the full decode.
+    decoder->PostHasTransparencyIfNeeded(transparency);
+
+    // We have the metadata we're looking for, so stop here, before we allocate
+    // buffers below.
+    return decoder->DoTerminate(png_ptr, TerminalState::SUCCESS);
+  }
+
+  if (decoder->mInProfile && decoder->GetCMSOutputProfile()) {
+    qcms_data_type inType;
+    qcms_data_type outType;
+
+    uint32_t profileSpace = qcms_profile_get_color_space(decoder->mInProfile);
+    decoder->mUsePipeTransform = profileSpace != icSigGrayData;
+    if (decoder->mUsePipeTransform) {
+      // If the transform happens with SurfacePipe, it will be in RGBA if we
+      // have an alpha channel, because the swizzle and premultiplication
+      // happens after color management. Otherwise it will be in BGRA because
+      // the swizzle happens at the start.
+      if (transparency == TransparencyType::eAlpha) {
+        inType = QCMS_DATA_RGBA_8;
+        outType = QCMS_DATA_RGBA_8;
+      } else {
+        inType = gfxPlatform::GetCMSOSRGBAType();
+        outType = inType;
+      }
+    } else {
+      if (color_type & PNG_COLOR_MASK_ALPHA) {
+        inType = QCMS_DATA_GRAYA_8;
+        outType = gfxPlatform::GetCMSOSRGBAType();
+      } else {
+        inType = QCMS_DATA_GRAY_8;
+        outType = gfxPlatform::GetCMSOSRGBAType();
+      }
+    }
+
+    decoder->mTransform = qcms_transform_create(decoder->mInProfile, inType,
+                                                decoder->GetCMSOutputProfile(),
+                                                outType, (qcms_intent)intent);
+  } else if ((sRGBTag && decoder->mCMSMode == CMSMode::TaggedOnly) ||
+             decoder->mCMSMode == CMSMode::All) {
+    // If the transform happens with SurfacePipe, it will be in RGBA if we
+    // have an alpha channel, because the swizzle and premultiplication
+    // happens after color management. Otherwise it will be in OS_RGBA because
+    // the swizzle happens at the start.
+    if (transparency == TransparencyType::eAlpha) {
+      decoder->mTransform =
+          decoder->GetCMSsRGBTransform(SurfaceFormat::R8G8B8A8);
+    } else {
+      decoder->mTransform =
+          decoder->GetCMSsRGBTransform(SurfaceFormat::OS_RGBA);
+    }
+    decoder->mUsePipeTransform = true;
+  }
+
+#ifdef PNG_APNG_SUPPORTED
+  if (isAnimated) {
+    png_set_progressive_frame_fn(png_ptr, nsPNGDecoder::frame_info_callback,
+                                 nullptr);
+  }
+
+  if (png_get_first_frame_is_hidden(png_ptr, info_ptr)) {
+    decoder->mFrameIsHidden = true;
+  } else {
+#endif
+    nsresult rv = decoder->CreateFrame(FrameInfo{frameRect, isInterlaced});
+    if (NS_FAILED(rv)) {
+      png_error(decoder->mPNG, "CreateFrame failed");
+    }
+    MOZ_ASSERT(decoder->mImageData, "Should have a buffer now");
+#ifdef PNG_APNG_SUPPORTED
+  }
+#endif
+
+  if (decoder->mTransform && !decoder->mUsePipeTransform) {
+    decoder->mCMSLine =
+        static_cast<uint8_t*>(malloc(sizeof(uint32_t) * frameRect.Width()));
+    if (!decoder->mCMSLine) {
+      png_error(decoder->mPNG, "malloc of mCMSLine failed");
+    }
+  }
+
+  if (interlace_type == PNG_INTERLACE_ADAM7) {
+    if (frameRect.Height() <
+        INT32_MAX / (frameRect.Width() * int32_t(channels))) {
+      const size_t bufferSize =
+          channels * frameRect.Width() * frameRect.Height();
+
+      if (bufferSize > SurfaceCache::MaximumCapacity()) {
+        png_error(decoder->mPNG, "Insufficient memory to deinterlace image");
+      }
+
+      decoder->interlacebuf = static_cast<uint8_t*>(malloc(bufferSize));
+    }
+    if (!decoder->interlacebuf) {
+      png_error(decoder->mPNG, "malloc of interlacebuf failed");
+    }
+  }
+}
+
+void nsPNGDecoder::PostInvalidationIfNeeded() {
+  Maybe<SurfaceInvalidRect> invalidRect = mPipe.TakeInvalidRect();
+  if (!invalidRect) {
+    return;
+  }
+
+  PostInvalidation(invalidRect->mInputSpaceRect,
+                   Some(invalidRect->mOutputSpaceRect));
+}
+
+void nsPNGDecoder::row_callback(png_structp png_ptr, png_bytep new_row,
+                                png_uint_32 row_num, int pass) {
+  /* libpng comments:
+   *
+   * This function is called for every row in the image.  If the
+   * image is interlacing, and you turned on the interlace handler,
+   * this function will be called for every row in every pass.
+   * Some of these rows will not be changed from the previous pass.
+   * When the row is not changed, the new_row variable will be
+   * nullptr. The rows and passes are called in order, so you don't
+   * really need the row_num and pass, but I'm supplying them
+   * because it may make your life easier.
+   *
+   * For the non-nullptr rows of interlaced images, you must call
+   * png_progressive_combine_row() passing in the row and the
+   * old row.  You can call this function for nullptr rows (it will
+   * just return) and for non-interlaced images (it just does the
+   * memcpy for you) if it will make the code easier.  Thus, you
+   * can just do this for all cases:
+   *
+   *    png_progressive_combine_row(png_ptr, old_row, new_row);
+   *
+   * where old_row is what was displayed for previous rows.  Note
+   * that the first pass (pass == 0 really) will completely cover
+   * the old row, so the rows do not have to be initialized.  After
+   * the first pass (and only for interlaced images), you will have
+   * to pass the current row, and the function will combine the
+   * old row and the new row.
+   */
+  nsPNGDecoder* decoder =
+      static_cast<nsPNGDecoder*>(png_get_progressive_ptr(png_ptr));
+
+  if (decoder->mFrameIsHidden) {
+    return;  // Skip this frame.
+  }
+
+  MOZ_ASSERT_IF(decoder->IsFirstFrameDecode(), decoder->mNumFrames == 0);
+
+  while (pass > decoder->mPass) {
+    // Advance to the next pass. We may have to do this multiple times because
+    // libpng will skip passes if the image is so small that no pixels have
+    // changed on a given pass, but ADAM7InterpolatingFilter needs to be reset
+    // once for every pass to perform interpolation properly.
+    decoder->mPipe.ResetToFirstRow();
+    decoder->mPass++;
+  }
+
+  const png_uint_32 height =
+      static_cast<png_uint_32>(decoder->mFrameRect.Height());
+
+  if (row_num >= height) {
+    // Bail if we receive extra rows. This is especially important because if we
+    // didn't, we might overflow the deinterlacing buffer.
+    MOZ_ASSERT_UNREACHABLE("libpng producing extra rows?");
+    return;
+  }
+
+  // Note that |new_row| may be null here, indicating that this is an interlaced
+  // image and |row_callback| is being called for a row that hasn't changed.
+  MOZ_ASSERT_IF(!new_row, decoder->interlacebuf);
+
+  if (decoder->interlacebuf) {
+    uint32_t width = uint32_t(decoder->mFrameRect.Width());
+
+    // We'll output the deinterlaced version of the row.
+    uint8_t* rowToWrite =
+        decoder->interlacebuf + (row_num * decoder->mChannels * width);
+
+    // Update the deinterlaced version of this row with the new data.
+    png_progressive_combine_row(png_ptr, rowToWrite, new_row);
+
+    decoder->WriteRow(rowToWrite);
+  } else {
+    decoder->WriteRow(new_row);
+  }
+}
+
+void nsPNGDecoder::WriteRow(uint8_t* aRow) {
+  MOZ_ASSERT(aRow);
+
+  uint8_t* rowToWrite = aRow;
+  uint32_t width = uint32_t(mFrameRect.Width());
+
+  // Apply color management to the row, if necessary, before writing it out.
+  // This is only needed for grayscale images.
+  if (mTransform && !mUsePipeTransform) {
+    MOZ_ASSERT(mCMSLine);
+    qcms_transform_data(mTransform, rowToWrite, mCMSLine, width);
+    rowToWrite = mCMSLine;
+  }
+
+  // Write this row to the SurfacePipe.
+  DebugOnly<WriteState> result =
+      mPipe.WriteBuffer(reinterpret_cast<uint32_t*>(rowToWrite));
+  MOZ_ASSERT(WriteState(result) != WriteState::FAILURE);
+
+  PostInvalidationIfNeeded();
+}
+
+void nsPNGDecoder::DoTerminate(png_structp aPNGStruct, TerminalState aState) {
+  // Stop processing data. Note that we intentionally ignore the return value of
+  // png_process_data_pause(), which tells us how many bytes of the data that
+  // was passed to png_process_data() have not been consumed yet, because now
+  // that we've reached a terminal state, we won't do any more decoding or call
+  // back into libpng anymore.
+  png_process_data_pause(aPNGStruct, /* save = */ false);
+
+  mNextTransition = aState == TerminalState::SUCCESS
+                        ? Transition::TerminateSuccess()
+                        : Transition::TerminateFailure();
+}
+
+void nsPNGDecoder::DoYield(png_structp aPNGStruct) {
+  // Pause data processing. png_process_data_pause() returns how many bytes of
+  // the data that was passed to png_process_data() have not been consumed yet.
+  // We use this information to tell StreamingLexer where to place us in the
+  // input stream when we come back from the yield.
+  png_size_t pendingBytes = png_process_data_pause(aPNGStruct,
+                                                   /* save = */ false);
+
+  MOZ_ASSERT(pendingBytes < mLastChunkLength);
+  size_t consumedBytes = mLastChunkLength - min(pendingBytes, mLastChunkLength);
+
+  mNextTransition =
+      Transition::ContinueUnbufferedAfterYield(State::PNG_DATA, consumedBytes);
+}
+
+nsresult nsPNGDecoder::FinishInternal() {
+  // We shouldn't be called in error cases.
+  MOZ_ASSERT(!HasError(), "Can't call FinishInternal on error!");
+
+  if (IsMetadataDecode()) {
+    return NS_OK;
+  }
+
+  int32_t loop_count = 0;
+#ifdef PNG_APNG_SUPPORTED
+  if (png_get_valid(mPNG, mInfo, PNG_INFO_acTL)) {
+    int32_t num_plays = png_get_num_plays(mPNG, mInfo);
+    loop_count = num_plays - 1;
+  }
+#endif
+
+  if (InFrame()) {
+    EndImageFrame();
+  }
+  PostDecodeDone(loop_count);
+
+  return NS_OK;
+}
+
+#ifdef PNG_APNG_SUPPORTED
+// got the header of a new frame that's coming
+void nsPNGDecoder::frame_info_callback(png_structp png_ptr,
+                                       png_uint_32 frame_num) {
+  nsPNGDecoder* decoder =
+      static_cast<nsPNGDecoder*>(png_get_progressive_ptr(png_ptr));
+
+  // old frame is done
+  decoder->EndImageFrame();
+
+  const bool previousFrameWasHidden = decoder->mFrameIsHidden;
+
+  if (!previousFrameWasHidden && decoder->IsFirstFrameDecode()) {
+    // We're about to get a second non-hidden frame, but we only want the first.
+    // Stop decoding now. (And avoid allocating the unnecessary buffers below.)
+    return decoder->DoTerminate(png_ptr, TerminalState::SUCCESS);
+  }
+
+  // Only the first frame can be hidden, so unhide unconditionally here.
+  decoder->mFrameIsHidden = false;
+
+  // Save the information necessary to create the frame; we'll actually create
+  // it when we return from the yield.
+  const OrientedIntRect frameRect(
+      png_get_next_frame_x_offset(png_ptr, decoder->mInfo),
+      png_get_next_frame_y_offset(png_ptr, decoder->mInfo),
+      png_get_next_frame_width(png_ptr, decoder->mInfo),
+      png_get_next_frame_height(png_ptr, decoder->mInfo));
+  const bool isInterlaced = bool(decoder->interlacebuf);
+
+#  ifndef MOZ_EMBEDDED_LIBPNG
+  // if using system library, check frame_width and height against 0
+  if (frameRect.width == 0) {
+    png_error(png_ptr, "Frame width must not be 0");
+  }
+  if (frameRect.height == 0) {
+    png_error(png_ptr, "Frame height must not be 0");
+  }
+#  endif
+
+  const FrameInfo info{frameRect, isInterlaced};
+
+  // If the previous frame was hidden, skip the yield (which will mislead the
+  // caller, who will think the previous frame was real) and just allocate the
+  // new frame here.
+  if (previousFrameWasHidden) {
+    if (NS_FAILED(decoder->CreateFrame(info))) {
+      return decoder->DoTerminate(png_ptr, TerminalState::FAILURE);
+    }
+
+    MOZ_ASSERT(decoder->mImageData, "Should have a buffer now");
+    return;  // No yield, so we'll just keep decoding.
+  }
+
+  // Yield to the caller to notify them that the previous frame is now complete.
+  decoder->mNextFrameInfo = Some(info);
+  return decoder->DoYield(png_ptr);
+}
+#endif
+
+void nsPNGDecoder::end_callback(png_structp png_ptr, png_infop info_ptr) {
+  /* libpng comments:
+   *
+   * this function is called when the whole image has been read,
+   * including any chunks after the image (up to and including
+   * the IEND).  You will usually have the same info chunk as you
+   * had in the header, although some data may have been added
+   * to the comments and time fields.
+   *
+   * Most people won't do much here, perhaps setting a flag that
+   * marks the image as finished.
+   */
+
+  nsPNGDecoder* decoder =
+      static_cast<nsPNGDecoder*>(png_get_progressive_ptr(png_ptr));
+
+  // We shouldn't get here if we've hit an error
+  MOZ_ASSERT(!decoder->HasError(), "Finishing up PNG but hit error!");
+
+  return decoder->DoTerminate(png_ptr, TerminalState::SUCCESS);
+}
+
+void nsPNGDecoder::error_callback(png_structp png_ptr,
+                                  png_const_charp error_msg) {
+  MOZ_LOG(sPNGLog, LogLevel::Error, ("libpng error: %s\n", error_msg));
+  png_longjmp(png_ptr, 1);
+}
+
+void nsPNGDecoder::warning_callback(png_structp png_ptr,
+                                    png_const_charp warning_msg) {
+  MOZ_LOG(sPNGLog, LogLevel::Warning, ("libpng warning: %s\n", warning_msg));
+}
+
+Maybe<Telemetry::HistogramID> nsPNGDecoder::SpeedHistogram() const {
+  return Some(Telemetry::IMAGE_DECODE_SPEED_PNG);
+}
+
+bool nsPNGDecoder::IsValidICOResource() const {
+  // Only 32-bit RGBA PNGs are valid ICO resources; see here:
+  //   http://blogs.msdn.com/b/oldnewthing/archive/2010/10/22/10079192.aspx
+
+  // If there are errors in the call to png_get_IHDR, the error_callback in
+  // nsPNGDecoder.cpp is called.  In this error callback we do a longjmp, so
+  // we need to save the jump buffer here. Otherwise we'll end up without a
+  // proper callstack.
+  if (setjmp(png_jmpbuf(mPNG))) {
+    // We got here from a longjmp call indirectly from png_get_IHDR
+    return false;
+  }
+
+  png_uint_32 png_width,  // Unused
+      png_height;         // Unused
+
+  int png_bit_depth, png_color_type;
+
+  if (png_get_IHDR(mPNG, mInfo, &png_width, &png_height, &png_bit_depth,
+                   &png_color_type, nullptr, nullptr, nullptr)) {
+    return ((png_color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+             png_color_type == PNG_COLOR_TYPE_RGB) &&
+            png_bit_depth == 8);
+  } else {
+    return false;
+  }
+}
+
+}  // namespace image
+}  // namespace mozilla