BUG #5246: Misleading/inconsistent SQLSTATE behavior

The following bug has been logged online:

Bug reference:      5246
Logged by:          Chris Travers
Email address:      chris.travers@gmail.com
PostgreSQL version: 8.1.18
Operating system:   Fedora Linux 12
Description:        Misleading/inconsistent SQLSTATE behavior
Details:

Hi all;

I am noticing that that a failed database connection results in an unusable
SQLSTATE in libpq, and a very different SQLSTATE than the backend
registers.

For example, if a connection fails due to a database not found, the backend
registers 3D000 as a SQL state, but the front-end registers 25P01.  If a
login fails, the back-end registers 28000 but the front-end registers 25P01
again.

25P01 is "no_active_sql_transaction" and provides little information to the
programmer as to how to handle the error.  I may be missing something but
the error looks to be entirely meaningless as it relates to a failed
connection attempt as I, as a programmer, am loathe to trust that a generic
transaction-related status message would be only used to track connection
problems.

From a programming perspective, it would be ideal for the same SQLSTATE
triggered on the back-end to be available to the front-end.    This leads to
a number of very substandard workarounds.  This might not be addressable
within stable versions, but it would be very nice to see it fixed.

Best Wishes,
Chris Travers