Index: src/ZPublisher/HTTPResponse.py
===================================================================
--- src/ZPublisher/HTTPResponse.py	(revision 121442)
+++ src/ZPublisher/HTTPResponse.py	(working copy)
@@ -338,7 +338,7 @@
             name = literal and name or key
             self.headers[name] = value
 
-    def appendHeader(self, name, value, delimiter=","):
+    def appendHeader(self, name, value, delimiter=", "):
         """ Append a value to an HTTP return header.
 
         Set an HTTP return header "name" with value "value",
@@ -353,7 +353,7 @@
         headers = self.headers
         if headers.has_key(name):
             h = headers[name]
-            h = "%s%s\r\n\t%s" % (h, delimiter, value)
+            h = "%s%s%s" % (h, delimiter, value)
         else:
             h = value
         self.setHeader(name,h, scrubbed=True)
Index: src/ZPublisher/tests/testHTTPResponse.py
===================================================================
--- src/ZPublisher/tests/testHTTPResponse.py	(revision 121442)
+++ src/ZPublisher/tests/testHTTPResponse.py	(working copy)
@@ -445,13 +445,13 @@
         response = self._makeOne()
         response.setHeader('foo', 'bar')
         response.appendHeader('foo', 'foo')
-        self.assertEqual(response.headers.get('foo'), 'bar,\r\n\tfoo')
+        self.assertEqual(response.headers.get('foo'), 'bar, foo')
 
     def test_appendHeader_w_existing_case_insenstative(self):
         response = self._makeOne()
         response.setHeader('xxx', 'bar')
         response.appendHeader('XXX', 'foo')
-        self.assertEqual(response.headers.get('xxx'), 'bar,\r\n\tfoo')
+        self.assertEqual(response.headers.get('xxx'), 'bar, foo')
 
     def test_appendHeader_drops_CRLF(self):
         # RFC2616 disallows CRLF in a header value.