Rework echo_hidden for \sf and \ef from commit e4d2817.

PSQLexec's error reporting turns out to be too verbose for this case, so
revert to using PQexec instead with minimal error reporting. Prior to
calling PQexec, we call a function that mimics just the echo_hidden
piece of PSQLexec.

src/bin/psql/command.c

@@ -2924,6 +2924,34 @@ do_watch(PQExpBuffer query_buf, long sleep)
 	return true;
 }
 
+/*
+ * a little code borrowed from PSQLexec() to manage ECHO_HIDDEN output.
+ * returns true unless we have ECHO_HIDDEN_NOEXEC.
+ */
+static bool
+lookup_function_echo_hidden(char * query)
+{
+	if (pset.echo_hidden != PSQL_ECHO_HIDDEN_OFF)
+	{
+		printf(_("********* QUERY **********\n"
+				 "%s\n"
+				 "**************************\n\n"), query);
+		fflush(stdout);
+		if (pset.logfile)
+		{
+			fprintf(pset.logfile,
+					_("********* QUERY **********\n"
+					  "%s\n"
+					  "**************************\n\n"), query);
+			fflush(pset.logfile);
+		}
+
+		if (pset.echo_hidden == PSQL_ECHO_HIDDEN_NOEXEC)
+			return false;
+	}
+	return true;
+}
+
 /*
  * This function takes a function description, e.g. "x" or "x(int)", and
  * issues a query on the given connection to retrieve the function's OID
@@ -2945,8 +2973,9 @@ lookup_function_oid(const char *desc, Oid *foid)
 	appendStringLiteralConn(query, desc, pset.db);
 	appendPQExpBuffer(query, "::pg_catalog.%s::pg_catalog.oid",
 					  strchr(desc, '(') ? "regprocedure" : "regproc");
-
-	res = PSQLexec(query->data);
+	if (!lookup_function_echo_hidden(query->data))
+		return false;
+	res = PQexec(pset.db, query->data);
 	if (PQresultStatus(res) == PGRES_TUPLES_OK && PQntuples(res) == 1)
 		*foid = atooid(PQgetvalue(res, 0, 0));
 	else
@@ -2975,7 +3004,9 @@ get_create_function_cmd(Oid oid, PQExpBuffer buf)
 	query = createPQExpBuffer();
 	printfPQExpBuffer(query, "SELECT pg_catalog.pg_get_functiondef(%u)", oid);
 
-	res = PSQLexec(query->data);
+	if (!lookup_function_echo_hidden(query->data))
+		return false;
+	res = PQexec(pset.db, query->data);
 	if (PQresultStatus(res) == PGRES_TUPLES_OK && PQntuples(res) == 1)
 	{
 		resetPQExpBuffer(buf);