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> 	// additional table used only during conversion
> 	@define('USERCONV_TABLE', $table_prefix . 'userconv');
> 
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< 			phpbb_check_username_collisions();
---
> 			phpbb_create_userconv_table();
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> 			array(
> 				'target'	=> USERCONV_TABLE,
> 				'query_first'   => array('target', $convert->truncate_statement . USERCONV_TABLE),
> 
> 
> 				array('user_id',			'users.user_id', 	''),
> 				array('username_clean',		'users.username',	array('function1' => 'phpbb_set_encoding', 'function2' => 'utf8_clean_string')),
> 			),
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> 				'execute_first'	=> 'phpbb_check_username_collisions();',