Allowing groupsideblockmaxgroups to be set as blank (Bug #1377371)

Also allow a text field to change from 0 to blank. Currently it doesn't
update the user even though they are different.

Change-Id: I4dcc9dd469ec7525c80c29f0207487d8f26fff34
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>

htdocs/account/index.php

@@ -224,13 +224,12 @@ function accountprefs_submit(Pieform $form, $values) {
 
     // Set user account preferences
     foreach ($expectedprefs as $eprefkey => $epref) {
-        if (isset($values[$eprefkey]) && $values[$eprefkey] != get_account_preference($USER->get('id'), $eprefkey)) {
+        if (isset($values[$eprefkey]) && $values[$eprefkey] !== get_account_preference($USER->get('id'), $eprefkey)) {
             $USER->set_account_preference($eprefkey, $values[$eprefkey]);
         }
     }
 
     $returndata = array();
-
     if (isset($values['username']) && $values['username'] != $USER->get('username')) {
         $USER->username = $values['username'];
         $USER->commit();

htdocs/lib/mahara.php

@@ -2950,10 +2950,9 @@ function profile_sideblock() {
     $data['pendingfriendsmessage'] = $data['pendingfriends'] == 1 ? get_string('pendingfriend') : get_string('pendingfriends');
     // Check if we want to limit the displayed groups by the account setting
     $limitto = null;
-    if ($limit = $USER->get_account_preference('groupsideblockmaxgroups')) {
-        if (!empty($limit)) {
-            $limitto = intval($limit);
-        }
+    $limit = $USER->get_account_preference('groupsideblockmaxgroups');
+    if (isset($limit) && is_numeric($limit)) {
+        $limitto = intval($limit);
     }
     $sort = null;
     if ($sortorder = $USER->get_account_preference('groupsideblocksortby')) {

htdocs/lib/user.php

@@ -201,7 +201,7 @@ function expected_account_preferences() {
                  'addremovecolumns' => 0,
                  'maildisabled'   => 0,
                  'tagssideblockmaxtags' => get_config('tagssideblockmaxtags'),
-                 'groupsideblockmaxgroups' => 0,
+                 'groupsideblockmaxgroups' => '',
                  'groupsideblocksortby' => 'alphabetical',
                  'hiderealname'   => 0,
                  'multipleblogs' => 0,
@@ -363,7 +363,7 @@ function general_account_prefs_form_elements($prefs) {
         'size'         => 4,
         'title'        => get_string('limitto1', 'blocktype.mygroups'),
         'description'  => get_string('limittodescsideblock1', 'blocktype.mygroups'),
-        'defaultvalue' => isset($prefs->groupsideblockmaxgroups) ? $prefs->groupsideblockmaxgroups : 0,
+        'defaultvalue' => isset($prefs->groupsideblockmaxgroups) ? $prefs->groupsideblockmaxgroups : '',
         'rules'        => array('regex' => '/^[0-9]*$/', 'minvalue' => 0, 'maxvalue' => 1000),
     );
     $elements['groupsideblocksortby'] = array(