Upgrade blink side ReadPixels size validation to consider ES3 pack parameters.

third_party/WebKit/Source/modules/webgl/WebGLRenderingContextBase.cpp

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 3788 matching lines @@
     case GL_FLOAT:
         return DOMArrayBufferView::TypeFloat32;
     case GL_HALF_FLOAT_OES:
         return DOMArrayBufferView::TypeUint16;
     default:
         ASSERT_NOT_REACHED();
         return DOMArrayBufferView::TypeUint8;
     }
 }
 
+WebGLImageConversion::PixelStoreParams WebGLRenderingContextBase::getPackPixelStoreParams()
+{
+    WebGLImageConversion::PixelStoreParams params;
+    params.alignment = m_packAlignment;
+    return params;
+}
+
+WebGLImageConversion::PixelStoreParams WebGLRenderingContextBase::getUnpackPixelStoreParams()
+{
+    WebGLImageConversion::PixelStoreParams params;
+    params.alignment = m_unpackAlignment;
+    return params;
+}
+
 bool WebGLRenderingContextBase::validateReadPixelsFuncParameters(GLsizei width, GLsizei height, GLenum format, GLenum type, long long bufferSize)
 {
     if (!validateReadPixelsFormatAndType(format, type))
         return false;
     WebGLFramebuffer* readFramebufferBinding = nullptr;
     GLenum readBufferInternalFormat = 0, readBufferType = 0;
     if (!validateReadBufferAndGetInfo("readPixels", readFramebufferBinding, &readBufferInternalFormat, &readBufferType))
         return false;
     if (!validateReadPixelsFormatTypeCombination(format, type, readBufferInternalFormat, readBufferType))
         return false;
 
-    // Calculate array size, taking into consideration of PACK_ALIGNMENT.
-    unsigned totalBytesRequired = 0;
-    unsigned padding = 0;
-    GLenum error = WebGLImageConversion::computeImageSizeInBytes(format, type, width, height, 1, m_packAlignment, &totalBytesRequired, &padding);
+    // Calculate array size, taking into consideration of pack parameters.
+    unsigned totalBytesRequired = 0, totalSkipBytes = 0;
+    GLenum error = WebGLImageConversion::computeImageSizeInBytes(format, type, width, height, 1, getPackPixelStoreParams(), &totalBytesRequired, 0, &totalSkipBytes);
     if (error != GL_NO_ERROR) {
         synthesizeGLError(error, "readPixels", "invalid dimensions");
         return false;
     }
-    if (bufferSize < static_cast<long long>(totalBytesRequired)) {
+    if (bufferSize < static_cast<long long>(totalBytesRequired + totalSkipBytes)) {
         synthesizeGLError(GL_INVALID_OPERATION, "readPixels", "buffer is not large enough for dimensions");
         return false;
     }
     return true;
 }
 
 void WebGLRenderingContextBase::readPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, DOMArrayBufferView* pixels)
 {
     if (isContextLost())
         return;
@@ skipping 2016 matching lines @@
         if (pixels->type() != DOMArrayBufferView::TypeUint16) {
             synthesizeGLError(GL_INVALID_OPERATION, functionName, "type HALF_FLOAT_OES but ArrayBufferView is not NULL and not Uint16Array");
             return false;
         }
         break;
     default:
         ASSERT_NOT_REACHED();
     }
 
     unsigned totalBytesRequired;
-    GLenum error = WebGLImageConversion::computeImageSizeInBytes(format, type, width, height, depth, m_unpackAlignment, &totalBytesRequired, 0);
+    GLenum error = WebGLImageConversion::computeImageSizeInBytes(format, type, width, height, depth, getUnpackPixelStoreParams(), &totalBytesRequired, 0, 0);
     if (error != GL_NO_ERROR) {
         synthesizeGLError(error, functionName, "invalid texture dimensions");
         return false;
     }
     if (pixels->byteLength() < totalBytesRequired) {
-        if (m_unpackAlignment != 1) {
-            error = WebGLImageConversion::computeImageSizeInBytes(format, type, width, height, depth, 1, &totalBytesRequired, 0);
-            if (pixels->byteLength() == totalBytesRequired) {
-                synthesizeGLError(GL_INVALID_OPERATION, functionName, "ArrayBufferView not big enough for request with UNPACK_ALIGNMENT > 1");
-                return false;
-            }
-        }
         synthesizeGLError(GL_INVALID_OPERATION, functionName, "ArrayBufferView not big enough for request");
         return false;
     }
     return true;
 }
 
 bool WebGLRenderingContextBase::validateCopyTexSubImage(const char* functionName, GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLint x, GLint y, GLsizei width, GLsizei height)
 {
     if (!validateTexFuncLevel(functionName, target, level))
         return false;
@@ skipping 1043 matching lines @@
         webContext()->pixelStorei(GL_UNPACK_ALIGNMENT, 1);
 }
 
 void WebGLRenderingContextBase::restoreUnpackParameters()
 {
     if (m_unpackAlignment != 1)
         webContext()->pixelStorei(GL_UNPACK_ALIGNMENT, m_unpackAlignment);
 }
 
 } // namespace blink