Fix user list extra field advanced search form see BT#12607

main/admin/user_list.php

@@ -299,10 +299,10 @@ function prepare_user_sql_query($is_count)
     }
 
     $variables = Session::read('variables_to_show', []);
-
+    if (!empty($variables)) {
         $extraField = new ExtraField('user');
-
         $extraFieldResult = [];
+        $extraFieldHasData = [];
         foreach ($variables as $variable) {
             if (isset($_GET['extra_'.$variable])) {
                 if (is_array($_GET['extra_'.$variable])) {
@@ -310,31 +310,53 @@ function prepare_user_sql_query($is_count)
                 } else {
                     $values = [$_GET['extra_'.$variable]];
                 }
-            $info = $extraField->get_handler_field_info_by_field_variable($variable);
+
+                if (empty($values)) {
+                    continue;
+                }
+
+                $info = $extraField->get_handler_field_info_by_field_variable(
+                    $variable
+                );
+
                 if (empty($info)) {
                     continue;
                 }
 
                 foreach ($values as $value) {
+                    if (empty($value)) {
+                        continue;
+                    }
                     if ($info['field_type'] == ExtraField::FIELD_TYPE_TAG) {
-                    $result = $extraField->getAllUserPerTag($info['id'], $value);
-                    $result = empty($result) ? [] : array_column($result, 'user_id');
+                        $result = $extraField->getAllUserPerTag(
+                            $info['id'],
+                            $value
+                        );
+                        $result = empty($result) ? [] : array_column(
+                            $result,
+                            'user_id'
+                        );
                     } else {
                         $result = UserManager::get_extra_user_data_by_value(
                             $variable,
                             $value
                         );
                     }
+                    $extraFieldHasData[] = true;
                     if (!empty($result)) {
-                    $extraFieldResult = array_merge($extraFieldResult, $result);
+                        $extraFieldResult = array_merge(
+                            $extraFieldResult,
+                            $result
+                        );
                     }
                 }
             }
         }
 
-    if (!empty($extraFieldResult)) {
+        if (!empty($extraFieldHasData)) {
             $sql .= " AND (u.id IN ('".implode("','", $extraFieldResult)."')) ";
         }
+    }
 
     // adding the filter to see the user's only of the current access_url
     if ((api_is_platform_admin() || api_is_session_admin())