Don't insert ASCII character with ctrl(w/o/ alt) or meta is on....

webkit/glue/editor_client_impl.cc

 // Copyright (c) 2006-2008 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.
 
 // The Mac interface forwards most of these commands to the application layer,
 // and I'm not really sure what to do about most of them.
 
 #include "config.h"
 #include "webkit/glue/editor_client_impl.h"
 
@@ skipping 593 matching lines @@
     }
     return false;
   }
 
   if (command.execute(evt)) {
     WebViewDelegate* d = web_view_->delegate();
     MaybeRecordCommand(d, command_name);
     return true;
   }
 
+  // Here we need to filter key events.
+  // On Gtk/Linux, it emits key events with ASCII text and ctrl on for ctrl-<x>.
+  // In Webkit, EditorClient::handleKeyboardEvent in 
+  // WebKit/gtk/WebCoreSupport/EditorClientGtk.cpp drop such events.
+  // On Mac, it emits key events with ASCII text and meta on for Command-<x>.
+  // These key events should not emit text insert event.
+  // Alt key would be used to insert alternative character, so we should let
+  // through. Also note that Ctrl-Alt combination equals to AltGr key which is 
+  // also used to insert alternative character.
+  // http://code.google.com/p/chromium/issues/detail?id=10846
+  // In summary, we can't think of a scenario where you'd use control w/o alt or
+  // meta to do insertion of a ASCII character.
+  // TODO(ukai): investigate more detail for various keyboard layout.
   if (evt->keyEvent()->text().length() == 1) {
     UChar ch = evt->keyEvent()->text()[0U];
 
     // Don't insert null or control characters as they can result in
     // unexpected behaviour
     if (ch < ' ')
       return false;
+    // Don't insert ASCII character if ctrl w/o alt or meta is on.
+    if (ch < 0x80 &&
+        ((evt->keyEvent()->ctrlKey() && !evt->keyEvent()->altKey()) ||
+        evt->keyEvent()->metaKey()))
+      return false;
   }
 
   if (!frame->editor()->canEdit())
     return false;
 
   return frame->editor()->insertText(evt->keyEvent()->text(), evt);
 }
 
 //
 // End of code block subject to Apple, Inc. copyright
@@ skipping 298 matching lines @@
   }
   return L"(UNKNOWN AFFINITY)";
 }
 
 std::wstring EditorClientImpl::Describe(WebCore::CSSStyleDeclaration* style) {
   // TODO(pamg): Implement me.  It's not clear what WebKit produces for this
   // (their [style description] method), and none of the layout tests provide
   // an example.  But because none of them use it, it's not yet important.
   return std::wstring();
 }