+ $php_version = phpversion();
+ $mysql_version = $wpdb->db_version();
+ $required_php_version = '4.3';
+ $required_mysql_version = '4.1.2';
+ $wp_version = '2.9';
+ $php_compat = version_compare( $php_version, $required_php_version, '>=' );
+ $mysql_compat = version_compare( $mysql_version, $required_mysql_version, '>=' ) || file_exists( WP_CONTENT_DIR . '/db.php' );
+
+ if ( !$mysql_compat && !$php_compat )
+ return new WP_Error( 'php_mysql_not_compatible', sprintf( __('The update cannot be installed because WordPress %1$s requires PHP version %2$s or higher and MySQL version %3$s or higher. You are running PHP version %4$s and MySQL version %5$s.'), $wp_version, $required_php_version, $required_mysql_version, $php_version, $mysql_version ) );
+ elseif ( !$php_compat )
+ return new WP_Error( 'php_not_compatible', sprintf( __('The update cannot be installed because WordPress %1$s requires PHP version %2$s or higher. You are running version %3$s.'), $wp_version, $required_php_version, $php_version ) );
+ elseif ( !$mysql_compat )
+ return new WP_Error( 'mysql_not_compatible', sprintf( __('The update cannot be installed because WordPress %1$s requires MySQL version %2$s or higher. You are running version %3$s.'), $wp_version, $required_mysql_version, $mysql_version ) );
+