Workaround bad bitmaps in clibpoard code

content/renderer/webclipboard_impl.cc

 // Copyright (c) 2013 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 "content/renderer/webclipboard_impl.h"
 
 #include "base/logging.h"
 #include "base/pickle.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 137 matching lines @@
     scw.WriteWebSmartPaste();
 }
 
 void WebClipboardImpl::writeImage(const WebImage& image,
                                   const WebURL& url,
                                   const WebString& title) {
   ScopedClipboardWriterGlue scw(client_);
 
   if (!image.isNull()) {
     const SkBitmap& bitmap = image.getSkBitmap();
+
+    // WriteBitmapFromPixels expects 32-bit data.
+    if (bitmap.config() != SkBitmap::kARGB_8888_Config)

[dcheng, 2014/05/19 19:44:59]

Hm... are you aware of any cases where we don't pass in an ARGB bitmap?
Otherwise, it seems to me like this should be a CHECK or DCHECK.

[piman, 2014/05/19 19:45:56]

Can't it be arbitrary?
E.g. what if the png is grayscale?

[dcheng, 2014/05/19 19:51:01]

I'm not an expert in this area, but this is the decoded bits of the image. I
would assume we always decode to a 32-bit ARGB to keep things simple.

[piman, 2014/05/19 22:50:00]

I'm not sure we want to make assumptions about code that is far far away in
another repo, when that assumption has security implications - see bug. Even if
it's true today, is there a test that verifies that it will stay true forever?

[piman, 2014/05/20 06:48:47]

OK, replaced by a DCHECK.

+      return;
     SkAutoLockPixels locked(bitmap);
-    scw.WriteBitmapFromPixels(bitmap.getPixels(), image.size());
+    void *pixels = bitmap.getPixels();
+    // TODO(piman): this should not be NULL, but it is. crbug.com/369621
+    if (!pixels)
+      return;
+    scw.WriteBitmapFromPixels(pixels, image.size());
   }
 
   if (!url.isEmpty()) {
     scw.WriteBookmark(title, url.spec());
 #if !defined(OS_MACOSX)
     // When writing the image, we also write the image markup so that pasting
     // into rich text editors, such as Gmail, reveals the image. We also don't
     // want to call writeText(), since some applications (WordPad) don't pick
     // the image if there is also a text format on the clipboard.
     // We also don't want to write HTML on a Mac, since Mail.app prefers to use
@@ skipping 43 matching lines @@
       return false;
 #endif
     default:
       NOTREACHED();
       return false;
   }
   return true;
 }
 
 }  // namespace content