Obsolete option default_manage_user_prefix

The option has been introduced in 2003 to solve performance issues on
installations with thousands of users.

The option was not documented in Admin Guide.

Paging (hardcoded 50 records) has been implemented in 2008.
After this, there is no longer the need for the option.
The performance is fine, even with more than 35k users.

Issue #24689

config_defaults_inc.php

@@ -3126,15 +3126,6 @@
  */
 $g_user_login_valid_regex = '/^([a-z\d\-.+_ ]+(@[a-z\d\-.]+\.[a-z]{2,4})?)$/i';
 
-/**
- * Default user name prefix used to filter the list of users in
- * manage_user_page.php.  Change this to 'A' (or any other
- * letter) if you have a lot of users in the system and loading
- * the manage users page takes a long time.
- * @global string $g_default_manage_user_prefix
- */
-$g_default_manage_user_prefix = 'ALL';
-
 /**
  * Default tag prefix used to filter the list of tags in
  * manage_tags_page.php.  Change this to 'A' (or any other
@@ -4481,7 +4472,6 @@
 	'default_language',
 	'default_limit_view',
 	'default_manage_tag_prefix',
-	'default_manage_user_prefix',
 	'default_new_account_access_level',
 	'default_notify_flags',
 	'default_project_view_status',

core/obsolete.php

@@ -219,4 +219,7 @@
 config_obsolete( 'differentiate_duplicates' );
 
 # changes in 2.12.0
-config_obsolete( 'session_handler' );
+config_obsolete( 'session_handler' );
+
+# changes in 2.17.0
+config_obsolete( 'default_manage_user_prefix' );

manage_user_page.php

@@ -61,7 +61,7 @@
 $t_lock_image = '<i class="fa fa-lock fa-lg" title="' . lang_get( 'protected' ) . '" />';
 
 $f_save = gpc_get_bool( 'save' );
-$f_filter = gpc_get_string( 'filter', config_get( 'default_manage_user_prefix' ) );
+$f_filter = gpc_get_string( 'filter', 'ALL' );
 $f_search = gpc_get_string( 'search', '');
 $f_page_number   = gpc_get_int( 'page_number', 1 );
 
@@ -165,17 +165,20 @@
 echo '    <div class="btn-group" >';
 foreach ( $t_prefix_array as $t_prefix => $t_caption ) {
 	if( $t_prefix === 'UNUSED' ) {
+		$t_search = '';
 		$t_title = ' title="[' . $t_unused_user_count . '] (' . lang_get( 'never_logged_in_title' ) . ')"';
 	} else if( $t_prefix === 'NEW' ) {
+		$t_search = '';
 		$t_title = ' title="[' . $t_new_user_count . '] (' . lang_get( '1_week_title' ) . ')"';
 	} else {
+		$t_search = $f_search;
 		$t_title = '';
 	}
 	$t_active = (string)$t_prefix === $f_filter ? 'active' : '';
 		print_manage_user_sort_link( 'manage_user_page.php',
 			$t_caption,
 			$c_sort,
-			$c_dir, null, $c_hide_inactive, $t_prefix, $f_search, $c_show_disabled,
+			$c_dir, null, $c_hide_inactive, $t_prefix, $t_search, $c_show_disabled,
 			'btn btn-xs btn-white btn-primary ' . $t_active );
 }
 echo '</div>';
@@ -187,13 +190,13 @@
 if( $f_filter === 'ALL' ) {
 	$t_where = '(1 = 1)';
 } else if( $f_filter === 'UNUSED' ) {
-    $t_where = '(login_count = 0) AND ( date_created = last_visit )';
+	$t_where = '(login_count = 0) AND ( date_created = last_visit )';
 } else if( $f_filter === 'NEW' ) {
-    $t_where = db_helper_compare_time( db_param(), '<=', 'date_created', $t_days_old );
-    $t_where_params[] = db_now();
+	$t_where = db_helper_compare_time( db_param(), '<=', 'date_created', $t_days_old );
+	$t_where_params[] = db_now();
 } else {
-    $t_where_params[] = $f_filter . '%';
-    $t_where = db_helper_like( 'username' );
+	$t_where_params[] = $f_filter . '%';
+	$t_where = db_helper_like( 'username' );
 }
 
 if( $f_search !== '' ) {