Index: trac/ticket/web_ui.py
===================================================================
--- trac/ticket/web_ui.py	(revision 6748)
+++ trac/ticket/web_ui.py	(working copy)
@@ -1258,7 +1258,6 @@
         elif field == 'keywords':
             old_list, new_list = old.split(), new.split()
             sep = ' '
-
         if (old_list, new_list) != (None, None):
             added = [tag.em(render_elt(x)) for x in new_list 
                      if x not in old_list]
@@ -1268,6 +1267,17 @@
             remvd = remvd and tag(separated(remvd, sep), " removed")
             if added or remvd:
                 rendered = tag(added, added and remvd and '; ', remvd)
+        if field in ('reporter', 'owner'):
+            if not (Chrome(self.env).show_email_addresses or 
+                    'EMAIL_VIEW' in req.perm(resource_new or ticket.resource)):
+                old = obfuscate_email_address(old)
+                new = obfuscate_email_address(new)
+            if old and not new:
+                rendered = tag(old, " deleted")
+            elif new and not old:
+                rendered = tag(new, " added")
+            elif old and new:
+                rendered = tag("changed from ", old, " to ", new)
         return rendered
 
     def grouped_changelog_entries(self, ticket, db, when=None):