Re: unclear enum error messages

Peter Eisentraut <peter_e@gmx.net> writes:
> There are a few error messages like this in the code:
>         /*
>          * We rely on being able to get the specific enum type from the calling
>          * expression tree.  The generic type mechanism should have ensured that
>          * both are of the same type.
>          */
>         enumtypoid = get_fn_expr_argtype(fcinfo->flinfo, 0);
>         if (enumtypoid == InvalidOid)
>                 ereport(ERROR,
>                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
>                                  errmsg("could not determine actual enum type")));

> First, isn't this an internal error?

Not necessarily; there are many code paths by which a function could get
called without argument-type info.  Thus the FEATURE_NOT_SUPPORTED
classification.

> What is an actual enum type?  And how should a user react if he got this
> message?  I would ask, "why not?".

Yeah, I would too, but without a concrete example to look at it's hard
to say if the situation could be improved.
        regards, tom lane