Setting host without port should keep old port

Source/core/html/HTMLAnchorElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 395 matching lines @@
     if (value.isEmpty())
         return;
     KURL url = href();
     if (!url.canSetHostOrPort())
         return;
 
     size_t separator = value.find(':');
     if (!separator)
         return;
 
-    if (separator == kNotFound)
-        url.setHostAndPort(value);
-    else {
+    if (separator == kNotFound) {
+        url.setHost(value);
+    } else {
         unsigned portEnd;
         unsigned port = parsePortFromStringPosition(value, separator + 1, portEnd);
         if (!port) {
             // http://dev.w3.org/html5/spec/infrastructure.html#url-decomposition-idl-attributes
             // specifically goes against RFC 3986 (p3.2) and
             // requires setting the port to "0" if it is set to empty string.
             url.setHostAndPort(value.substring(0, separator + 1) + "0");
         } else {
             if (isDefaultPortForProtocol(port, url.protocol()))
                 url.setHostAndPort(value.substring(0, separator));
@@ skipping 415 matching lines @@
 
     // The precision of current MouseOver trigger is too low to actually trigger preconnects.
     if (motivation == WebKit::WebPreconnectMotivationLinkMouseOver)
         return;
 
     preconnectToURL(url, motivation);
     m_hasIssuedPreconnect = true;
 }
 
 }