you won't get the error if you preface the * with the table name (or alias). For instance:

SELECT 'test', `$db`.`$oldtable`.*  
  FROM `$db`.`$oldtable`
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works.

However, MySQL warns not to rely on column order when selecting data with select *

So you should be able to do:

INSERT INTO `$db`.`$table` 
SELECT '', 'author', '', `$db`.`$oldtable`.* 
  FROM `$db`.`$oldtable`
[download]