pq: unexpected message 'E'; expected ReadyForQuery

[yansal]

We see this error regularly on a production system, and unfortunately we can't reproduce and there's very little information to help debugging.

It would be cool to add a 'E' case in this switch statement so that the error from Postgres can be shown.

pq/conn.go

Lines 1575 to 1585 in a8bb68e

	func (cn *conn) readReadyForQuery() {
	t, r := cn.recv1()
	switch t {
	case 'Z':
	cn.processReadyForQuery(r)
	return
	default:
	cn.bad = true
	errorf("unexpected message %q; expected ReadyForQuery", t)
	}
	}

[film42]

We've also started seeing errors that might be related to pq. I think the underlying error in our stack is being swallowed somewhere, but we've noticed connections will be opened and never closed. We had an app open 8K connections before process limits kicked in.

Disregard this. The cause was due to internal code. Sorry for the noise!

[arp242]

This should be fixed via #1220