Merge 139616

Source/WebCore/inspector/front-end/NetworkRequest.js

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 688 matching lines @@
      */
     _headerValue: function(headers, headerName)
     {
         headerName = headerName.toLowerCase();
         
         var values = [];
         for (var i = 0; i < headers.length; ++i) {
             if (headers[i].name.toLowerCase() === headerName)
                 values.push(headers[i].value);
         }
+        if (!values.length)
+            return undefined;
         // Set-Cookie values should be separated by '\n', not comma, otherwise cookies could not be parsed.
         if (headerName === "set-cookie")
             return values.join("\n");
         return values.join(", ");
     },
 
     /**
      * @return {?string|undefined}
      */
     get content()
@@ skipping 188 matching lines @@
     _pushFrame: function(object)
     {
         if (this._frames.length >= 100) {
             this._frames.splice(0, 10);
         }
         this._frames.push(object);
     },
 
     __proto__: WebInspector.Object.prototype
 }