In Zend\Db\Adapter\Adapter::createDriver() the class remove options from passed parameters.
It then passes the removed options array to Mysqli driver only, but not others.
However, Zend\Db\Adapter\Driver\Pdo\Connection expects options array in connection parameters.
It then passes this array to PDO.
It makes user unable to pass PDO options cause Adapter removes it from connection parameters.
Alternatively, one can pass charset=utf8 to DSN.
However this should be reflected in the documentation, because it still states charset option.
do not strip options from connection parameters
Do you already have a PR for this?
Actually- why wouldn't you pass charset as part of the connection parameters like username or password?
Like I said, this bug was reported 8 months ago.
May be you have reported the same bug few months later with PR and it got fixed.
If that is the case, this one should be closed.
It was fixed as part of #4973 and it is in develop, not master.