Re: psql 8.4 \c repeats version banner

Peter Eisentraut wrote:
> In 8.3, running \c from a file prints something like
> 
> You are now connected to database "postgres".
> 
> In 8.4 it prints
> 
> psql (8.4.1)
> You are now connected to database "postgres".
> 
> Is it intentional/sensible to repeat the startup banner every time the
> connection changes, or was this unintentionally introduced while the
> startup banner was reshuffled in 8.4?

I did some reseach on this.  I bet this behavior was added when we
decided to print the backend version warning banner on \c as well as
startup, because it is possible for the backend to be different version
from the backend originally used for psql startup.  The code that prints
the psql banner and the warning banner are in the same function and
share the same output line.

What I did in the attached patch is to add a boolean to
connection_warnings() to indicate whether it was being called on psql
startup or via \c, and to supress the psql banner on \c if the client
and server versions match:

	$ psql test
	psql (8.5devel)
	Type "help" for help.
	
	test=> \c test
	You are now connected to database "test".
	test=>

Any version mismatch will still print the psql banner for \c, which is
what I think we want.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

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