Better error reporting from extension scripts (Was: Extend ALTER OPERATOR)

Re: Tom Lane
> So the first part of that is great, but if your script file is
> large you probably won't be happy about having the whole thing
> repeated in the "QUERY" field.  So this needs some work on
> user-friendliness.

Does this really have to be addressed? It would be way better than it
is now, and errors during extension creation are rare and mostly for
developers only, so it doesn't have to be pretty.

> I'm inclined to think that maybe we'd be best off keeping the server
> end of it straightforward, and trying to teach psql to abbreviate the
> QUERY field in a useful way.  IIRC you get this same type of problem
> with very large SQL-language functions and suchlike.

I'd treat this as a separate patch, if it's considered to be a good
idea.

Christoph