Fix the crash of compressedTexImage3D for the WebGL2 conformance test page.

third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "modules/webgl/WebGL2RenderingContextBase.h"
 
 #include "bindings/modules/v8/WebGLAny.h"
 #include "core/html/HTMLCanvasElement.h"
 #include "core/html/HTMLImageElement.h"
@@ skipping 911 matching lines @@
 
 void WebGL2RenderingContextBase::compressedTexImage3D(GLenum target, GLint level, GLenum internalformat, GLsizei width, GLsizei height, GLsizei depth, GLint border, DOMArrayBufferView* data)
 {
     if (isContextLost())
         return;
 
     WebGLTexture* tex = validateTextureBinding("compressedTexImage3D", target, true);
     if (!tex)
         return;
 
+    if (internalformat != tex->getInternalFormat(target, level)) {

[qiankun, 2015/11/23 09:44:27]

CompressedTexImage3D is used to specify a three-dimensional texture image in a
compressed format. So no previously defined texture. This check should always
fail. Also ES3 doesn't have such limitation on internalformat matching. I think
you should do level validation here according your first CL.

+        synthesizeGLError(GL_INVALID_OPERATION, "compressedTexImage3D", "format does not match texture format");
+        return;
+    }
+
     if (tex->isImmutable()) {
         synthesizeGLError(GL_INVALID_OPERATION, "compressedTexImage3D", "attempted to modify immutable texture");
         return;
     }
 
     webContext()->compressedTexImage3D(target, level, internalformat, width, height, depth, border, data->byteLength(), data->baseAddress());
     tex->setLevelInfo(target, level, internalformat, width, height, depth, GL_UNSIGNED_BYTE);
 }
 
 void WebGL2RenderingContextBase::compressedTexSubImage3D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLenum format, DOMArrayBufferView* data)
@@ skipping 2183 matching lines @@
 GLenum WebGL2RenderingContextBase::boundFramebufferColorFormat()
 {
     if (m_readFramebufferBinding && m_readFramebufferBinding->object())
         return m_readFramebufferBinding->colorBufferFormat();
     if (m_requestedAttributes.alpha())
         return GL_RGBA;
     return GL_RGB;
 }
 
 } // namespace blink