Allow empty strings to be written to the clipboard

webkit/glue/webclipboard_impl.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 "webkit/glue/webclipboard_impl.h"
 
 #include "base/logging.h"
 #include "base/pickle.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
@@ skipping 217 matching lines @@
     scw.WriteHTML(UTF8ToUTF16(URLToImageMarkup(url, title)), "");
 #endif
   }
 }
 
 void WebClipboardImpl::writeDataObject(const WebDragData& data) {
   ScopedClipboardWriterGlue scw(client_);
 
   WebDropData data_object(data);
   // TODO(dcheng): Properly support text/uri-list here.
-  scw.WriteText(data_object.plain_text);
-  scw.WriteHTML(data_object.text_html, "");
+  if (!data_object.text.is_null())
+    scw.WriteText(data_object.text.string());
+  if (!data_object.html.is_null())
+    scw.WriteHTML(data_object.html.string(), "");
   // If there is no custom data, avoid calling WritePickledData. This ensures
   // that ScopedClipboardWriterGlue's dtor remains a no-op if the page didn't
   // modify the DataTransfer object, which is important to avoid stomping on
   // any clipboard contents written by extension functions such as
   // chrome.experimental.bookmarkManager.copy.
   if (!data_object.custom_data.empty()) {
     Pickle pickle;
     ui::WriteCustomDataToPickle(data_object.custom_data, &pickle);
     scw.WritePickledData(pickle, ui::Clipboard::GetWebCustomDataFormatType());
   }
@@ skipping 11 matching lines @@
       break;
 #endif
     default:
       NOTREACHED();
       return false;
   }
   return true;
 }
 
 }  // namespace webkit_glue