Hashes with type&value keys returned by the helpers get immediately unpacked

[ehuelsmann]

The helper returns a hash containing (in case of ByteString) two keys: type and value. That return value is recorded here:

https://github.com/ledgersmb/PGObject/blob/master/lib/PGObject.pm#L303

Then, the same mapper goes on to:

https://github.com/ledgersmb/PGObject/blob/master/lib/PGObject.pm#L306

Here, the hash gets unpacked and the $arg->{value} part of the ByteString::to_db() method gets assigned to $arg (note that there's no reference to the returned hash anymore at this point).

Then, execution continues to binding the parameters. At this point, you want to have the return value from ByteString's to_db() available, so we can use the 'type' key here:

https://github.com/ledgersmb/PGObject/blob/master/lib/PGObject.pm#L340

to bind to a pg_type. However, because we unpacked the returned hash in L306, there no longer is a hash and we pass on to the second half of the if statement, dropping everything after the first NULL (\0) character.