Jira issue originally created by user alexises:
the DQL Parser don't parse properly functions when a ScalarExpression is needed like of all case functions.
In fact first function token is interpreted as a T_IDENTIFIER and enter on line 1663 of Doctrine\ORM\Query\Parser class. in search of math operator, when not found this case considere that the token is a row element with no considération of the functions procession treated after.
fix of this bug consist to enclose the line 1672 by a if (!$this->_isFunction()).