Change name of game_cross.rows to usedrows (MariaDB compatibility)

db/upgrade.php

@@ -1556,10 +1556,12 @@ function xmldb_game_upgrade($oldversion) {
         $dbman->change_field_type($table, $field);
     }
 
-  if ($oldversion < ($ver = 2017061603)) {
+  if ($oldversion < ($ver = 2017061604)) {
         $table = new xmldb_table('game_cross');
         $field = new xmldb_field('usedcols', XMLDB_TYPE_INTEGER, '3', XMLDB_UNSIGNED, null, null, '0', 'id');
+        if (!$dbman->field_exists($table, $field)) {
             $dbman->add_field($table, $field);
+        }
 
         $field = new xmldb_field('cols', XMLDB_TYPE_INTEGER, '3', XMLDB_UNSIGNED, null, null, '0', 'id');
         if ($dbman->field_exists($table, $field)) {
@@ -1571,10 +1573,12 @@ function xmldb_game_upgrade($oldversion) {
         }
     }
 
-   if ($oldversion < ($ver = 2017061603)) {
+   if ($oldversion < ($ver = 2017061604)) {
         $table = new xmldb_table('game_cross');
         $field = new xmldb_field('usedrows', XMLDB_TYPE_INTEGER, '3', XMLDB_UNSIGNED, null, null, '0', 'id');
+        if (!$dbman->field_exists($table, $field)) {
             $dbman->add_field($table, $field);
+        }
 
         $field = new xmldb_field('rows', XMLDB_TYPE_INTEGER, '3', XMLDB_UNSIGNED, null, null, '0', 'id');
         if ($dbman->field_exists($table, $field)) {

version.php

@@ -35,7 +35,7 @@ if (!isset( $plugin)) {
 }
 
 $plugin->component = 'mod_game';  // Full name of the plugin (used for diagnostics).
-$plugin->version   = 2017061603;  // The current module version (Date: YYYYMMDDXX).
+$plugin->version   = 2017061604;  // The current module version (Date: YYYYMMDDXX).
 $plugin->requires  = 2010112400;  // Requires Moodle 2.0.
 $plugin->cron      = 0;           // Period for cron to check this module (secs).
 $plugin->release   = '2017-06-13';