Fix crash in BlitFramebufferCHROMIUM if a read or draw depth/stencil buffer is not present

gpu/command_buffer/service/gles2_cmd_decoder.cc

 // Copyright (c) 2012 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 "gpu/command_buffer/service/gles2_cmd_decoder.h"
 
 #include <limits.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
@@ skipping 7577 matching lines @@
   // and draw framebuffe is default framebuffer, but the other is fbo, they
   // always have no identical image.
   if (!read_framebuffer && !draw_framebuffer) {
     is_feedback_loop = FeedbackLoopTrue;
   } else if (!read_framebuffer || !draw_framebuffer) {
     is_feedback_loop = FeedbackLoopFalse;
   } else {
     DCHECK(read_framebuffer && draw_framebuffer);
     if ((mask & GL_DEPTH_BUFFER_BIT) != 0) {
       const Framebuffer::Attachment* depth_buffer_read =
-          read_framebuffer->GetAttachment(GL_DEPTH_ATTACHMENT);
+          read_framebuffer->GetDepthAttachment();
       const Framebuffer::Attachment* depth_buffer_draw =
-          draw_framebuffer->GetAttachment(GL_DEPTH_ATTACHMENT);
-      if (depth_buffer_draw &&
-          depth_buffer_draw->IsSameAttachment(depth_buffer_read)) {
+          draw_framebuffer->GetDepthAttachment();
+      if (!depth_buffer_draw || !depth_buffer_read) {
+        mask &= ~GL_DEPTH_BUFFER_BIT;
+      } else if (depth_buffer_draw->IsSameAttachment(depth_buffer_read)) {
         is_feedback_loop = FeedbackLoopTrue;
       }
     }
     if ((mask & GL_STENCIL_BUFFER_BIT) != 0) {
       const Framebuffer::Attachment* stencil_buffer_read =
-          read_framebuffer->GetAttachment(GL_STENCIL_ATTACHMENT);
+          read_framebuffer->GetStencilAttachment();
       const Framebuffer::Attachment* stencil_buffer_draw =
-          draw_framebuffer->GetAttachment(GL_STENCIL_ATTACHMENT);
-      if (stencil_buffer_draw &&
-          stencil_buffer_draw->IsSameAttachment(stencil_buffer_read)) {
+          draw_framebuffer->GetStencilAttachment();
+      if (!stencil_buffer_draw || !stencil_buffer_read) {
+        mask &= ~GL_STENCIL_BUFFER_BIT;
+      } else if (stencil_buffer_draw->IsSameAttachment(stencil_buffer_read)) {
         is_feedback_loop = FeedbackLoopTrue;
       }
     }
+    if (!mask)
+      return;
   }
 
   GLenum src_internal_format = GetBoundReadFramebufferInternalFormat();
   GLenum src_type = GetBoundReadFramebufferTextureType();
 
   bool read_buffer_has_srgb =
       GetColorEncodingFromInternalFormat(src_internal_format) == GL_SRGB;
   bool draw_buffers_has_srgb = false;
   if ((mask & GL_COLOR_BUFFER_BIT) != 0) {
     bool is_src_signed_int =
@@ skipping 10447 matching lines @@
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "base/macros.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu