In the continuing saga of FE/BE protocol revisions, add reporting of

initial values and runtime changes in selected parameters.  This gets
rid of the need for an initial 'select pg_client_encoding()' query in
libpq, bringing us back to one message transmitted in each direction
for a standard connection startup.  To allow server version to be sent
using the same GUC mechanism that handles other parameters, invent the
concept of a never-settable GUC parameter: you can 'show server_version'
but it's not settable by any GUC input source.  Create 'lc_collate' and
'lc_ctype' never-settable parameters so that people can find out these
settings without need for pg_controldata.  (These side ideas were all
discussed some time ago in pgsql-hackers, but not yet implemented.)

src/backend/utils/init/postinit.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/init/postinit.c,v 1.119 2003/02/19 14:31:26 ishii Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/init/postinit.c,v 1.120 2003/04/25 19:45:08 tgl Exp $
  *
  *
  *-------------------------------------------------------------------------
@@ -128,6 +128,9 @@ ReverifyMyDatabase(const char *name)
 	 * info out of the pg_database tuple.
 	 */
 	SetDatabaseEncoding(dbform->encoding);
+	/* Record it as a GUC internal option, too */
+	SetConfigOption("server_encoding", GetDatabaseEncodingName(),
+					PGC_INTERNAL, PGC_S_OVERRIDE);
 	/* If we have no other source of client_encoding, use server encoding */
 	SetConfigOption("client_encoding", GetDatabaseEncodingName(),
 					PGC_BACKEND, PGC_S_DEFAULT);
@@ -400,6 +403,12 @@ InitPostgres(const char *dbname, const char *username)
 	/* initialize client encoding */
 	InitializeClientEncoding();
 
+	/*
+	 * Now all default states are fully set up.  Report them to client
+	 * if appropriate.
+	 */
+	BeginReportingGUCOptions();
+
 	/*
 	 * Set up process-exit callback to do pre-shutdown cleanup.  This
 	 * should be last because we want shmem_exit to call this routine