From: Noah Misch <noah@leadboat.com>
Date: Thu, 9 Jul 2015 00:44:21 +0000 (-0400)
Subject: Fix null pointer dereference in "\c" psql command.
X-Git-Tag: REL9_6_BETA1~1712
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e135c3d99f4fcb03efa7b0b64445853ee2a74857;p=postgresql

Fix null pointer dereference in "\c" psql command.

The psql crash happened when no current connection existed.  (The second
new check is optional given today's undocumented NULL argument handling
in PQhost() etc.)  Back-patch to 9.0 (all supported versions).
---

diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 2728216022..6181a61678 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -1753,7 +1753,8 @@ do_connect(char *dbname, char *user, char *host, char *port)
 	 * positional syntax.
 	 */
 	keep_password =
-		((strcmp(user, PQuser(o_conn)) == 0) &&
+		(o_conn &&
+		 (strcmp(user, PQuser(o_conn)) == 0) &&
 		 (!host || strcmp(host, PQhost(o_conn)) == 0) &&
 		 (strcmp(port, PQport(o_conn)) == 0) &&
 		 !has_connection_string);
@@ -1880,7 +1881,8 @@ do_connect(char *dbname, char *user, char *host, char *port)
 	/* Tell the user about the new connection */
 	if (!pset.quiet)
 	{
-		if (param_is_newly_set(PQhost(o_conn), PQhost(pset.db)) ||
+		if (!o_conn ||
+			param_is_newly_set(PQhost(o_conn), PQhost(pset.db)) ||
 			param_is_newly_set(PQport(o_conn), PQport(pset.db)))
 		{
 			char	   *host = PQhost(pset.db);