Item13999: Remove the overwrite User Topic option

It doesn't work, and there are multiple issues.  Looking at the code,
this appears to have been broken as far back as Foswiki 1.0.9

TopicUserMappingContrib/data/System/BulkRegistration.txt

@@ -1,4 +1,4 @@
-%META:TOPICINFO{author="ProjectContributor" comment="" date="1456768091" format="1.1" version="1"}%
+%META:TOPICINFO{author="ProjectContributor" comment="" date="1456877772" format="1.1" version="1"}%
 %META:TOPICPARENT{name="AdminToolsCategory"}%
 ---+ Bulk Registration
 
@@ -27,9 +27,6 @@ Below are the details.
       * Set REGISTERTOPIC = %USERSWEB%.UnprocessedRegistrations
    * Use this to define where to log the bulk registration process. It will be saved to the %USERSWEB% web.
       * Set LOGTOPIC = %REGISTERTOPIC%Log
-   * Set this to 1 to make the bulk registration overwrite any existing user
-     topics. By default, existing user topics are left alone.
-      * Set OVERWRITEHOMETOPICS = 0
 
 ---++ The user table
 
@@ -107,7 +104,6 @@ Make sure that the extra fields also appear on the %SYSTEMWEB%.UserForm.
 <input type="hidden" name="action" value="bulkRegister" /><sticky>&nbsp;</sticky>
 <input type="submit" class="foswikiSubmit" value="Bulk Register these people" />
 <input type="hidden" name="LogTopic" value="%LOGTOPIC%" />
-<input type="hidden" name="OverwriteHomeTopics" value="%OVERWRITEHOMETOPICS%" />
 </form>
 
 ---++ <nop>%REGISTERTOPIC%

TopicUserMappingContrib/data/System/BulkRegistrationInputViewTemplate.txt

@@ -1,4 +1,4 @@
-%META:TOPICINFO{author="ProjectContributor" date="1456871285" format="1.1" version="1"}%
+%META:TOPICINFO{author="ProjectContributor" date="1456877772" format="1.1" version="1"}%
 %META:TOPICPARENT{name="BulkRegister"}%
 %{<verbatim class="tml">
 ===================================================
@@ -24,7 +24,6 @@
 <input type='submit' class='foswikiSubmit' value='Bulk Register these people' />
 <input type='hidden' name='redirectto' value='%TOPIC%' />
 <input type='hidden' name='LogTopic' value='%TOPIC%Log' /><br/>
-Overwrite home topics? <input type='checkbox' class='foswikiInputField' name='OverwriteHomeTopics' />
 </form>
 </div>"
 else="<div class='foswikiAlert'> *Bulk registration is restricted to Administrators.* </div>"}%

core/lib/Foswiki/UI/Register.pm

@@ -361,9 +361,6 @@ sub bulkRegister {
 
     my $settings = {};
 
-    # This gets set from the value in the BulkRegistrations topic
-    $settings->{doOverwriteTopics} = $query->param('OverwriteHomeTopics') || 0;
-
     unless ( $session->{users}->isAdmin($user) ) {
         throw Foswiki::OopsException(
             'accessdenied',
@@ -473,9 +470,6 @@ sub _registerSingleBulkUser {
     my ( $session, $fieldNames, $row, $settings ) = @_;
     ASSERT($row) if DEBUG;
 
-    my $doOverwriteTopics = defined $settings->{doOverwriteTopics}
-      || throw Error::Simple('No doOverwriteTopics');
-
     my $log = "---++ Registering $row->{WikiName}\n";
 
     #-- Ensure every required field exists
@@ -530,9 +524,7 @@ sub _registerSingleBulkUser {
         $log .=
 "$b1 $row->{WikiName} has been added to the password and user mapping managers\n";
 
-        if ( $settings->{doOverwriteTopics}
-            || !$session->topicExists( $row->{webName}, $row->{WikiName} ) )
-        {
+        if ( !$session->topicExists( $row->{webName}, $row->{WikiName} ) ) {
             $log .= _createUserTopic( $session, $row );
         }
         else {