In the spirit of TODO item

* Add use of 'const' for varibles in source tree
(which is misspelled, btw.)
I went through the front-end libpq code and did so. This affects in
particular the various accessor functions (such as PQdb() and
PQgetvalue()) as well as, by necessity, the internal helpers they use.

I have been really thorough in that regard, perhaps some people will find
it annoying that things like
char * foo = PQgetvalue(res, 0, 0)
will generate a warning. On the other hand it _should_ generate one. This
is no real compatibility break, although a few clients will have to be
fixed to suppress warnings. (Which again would be in the spirit of the
above TODO.)

In addition I replaced some int's by size_t's and removed some warnings
(and generated some new ones -- grmpf!). Also I rewrote PQoidStatus (so it
actually honors the const!) and supplied a new function PQoidValue that
returns a proper Oid type. This is only front-end stuff, none of the
communicaton stuff was touched.


The psql patch also adds some new consts to honor the new libpq situation,
as well as fixes a fatal condition that resulted when using the -V
(--version) option and there is no database listening.


So, to summarize, the psql you should definitely put in (with or without
the libpq). If you think I went too far with the const-mania in libpq, let
me know and I'll make adjustments. If you approve it, I will also update
the docs.

        -Peter

--
Peter Eisentraut                  Sernanders vaeg 10:115

src/bin/psql/command.c

@@ -828,7 +828,7 @@ do_connect(const char *new_dbname, const char *new_user, PsqlSettings *pset)
 	PGconn	   *oldconn = pset->db;
 	const char *dbparam = NULL;
 	const char *userparam = NULL;
-	char	   *pwparam = NULL;
+	const char *pwparam = NULL;
 	char	   *prompted_password = NULL;
 	char	   *prompted_user = NULL;
 	bool		need_pass;