Bug 685552 - Email auto-completion causes server to thrash

Bugzilla/Config/UserMatch.pm

@@ -47,6 +47,12 @@ sub get_param_list {
   },
 
   {
+   name    => 'ajax_user_autocompletion', 
+   type    => 'b', 
+   default => '1', 
+  },
+
+  {
    name    => 'maxusermatches',
    type    => 't',
    default => '1000',

Bugzilla/Mailer.pm

@@ -171,6 +171,8 @@ sub MessageToMTA {
     Bugzilla::Hook::process('mailer_before_send', 
                             { email => $email, mailer_args => \@args });
 
+    return if $email->header('to') eq '';
+
     if ($method eq "Test") {
         my $filename = bz_locations()->{'datadir'} . '/mailer.testfile';
         open TESTFILE, '>>', $filename;

docs/en/xml/administration.xml

@@ -864,7 +864,12 @@
             contains parameters for how user names can be queried and matched
             when entered.
           </para>
-
+          <para>
+            Another setting called 'ajax_user_autocompletion' enables certain
+            user fields to display a list of matched user names as a drop down after typing 
+            a few characters. Note that it is recommended to use mod_perl when
+            enabling 'ajax_user_autocompletion'.
+          </para>
         </section>
 
   </section>

template/en/default/admin/params/usermatch.html.tmpl

@@ -29,6 +29,9 @@
                      "needs to be selected. This option should not be enabled on " _
                      "sites where there are a large number of users.",
 
+  ajax_user_autocompletion => "If this option is set, typing characters in a certain user " _
+                              "fields will display a list of matches that can be selected from.", 
+
   maxusermatches => "Search for no more than this many matches.<br> " _
                     "If set to '1', no users will be displayed on ambiguous matches. " _
                     "This is useful for user privacy purposes.<br> " _

template/en/default/global/userselect.html.tmpl

@@ -79,7 +79,7 @@
   [% END %]
 </select>
 [% ELSE %]
-  [% IF id && feature_enabled('jsonrpc') %]
+  [% IF feature_enabled('jsonrpc') && Param('ajax_user_autocompletion') && id %]
     <div id="[% id FILTER html %]_autocomplete" 
          [% IF classes %] class="[% classes.join(' ') FILTER html %]" [% END %]>
   [% END %]  
@@ -94,7 +94,7 @@
     [% IF size %] size="[% size FILTER html %]" [% END %]
     [% IF id %] id="[% id FILTER html %]" [% END %]
   >
-  [% IF id && feature_enabled('jsonrpc') %]
+  [% IF feature_enabled('jsonrpc') && Param('ajax_user_autocompletion') && id %]
     <div id="[% id FILTER html %]_autocomplete_container"></div>
     </div>  
     <script type="text/javascript">