Change the built-in default socket directory to be /var/run/postgresql.
For backwards compatibility with (probably non-libpq-based) clients that
might still expect to find the socket in /tmp, also create a socket in
/tmp.  This is to resolve communication problems with clients operating
under systemd's PrivateTmp environment, which won't be using the same
global /tmp directory as the server; see bug #825448.

Note that we apply the socket directory change at the level of the
hard-wired defaults in the C code, not by just twiddling the setting in
postgresql.conf.sample; this is so that the change will take effect on
server package update, without requiring any existing postgresql.conf
to be updated.  (Of course, a user who dislikes this behavior can still
override it via postgresql.conf.)

This patch must be applied after postgresql-multi-sockets.patch, at
least until 9.3 when that will be part of the upstream package.


diff -Naur postgresql-9.2.0.sockets/contrib/pg_upgrade/test.sh postgresql-9.2.0/contrib/pg_upgrade/test.sh
--- postgresql-9.2.0.sockets/contrib/pg_upgrade/test.sh	2012-09-06 17:26:17.000000000 -0400
+++ postgresql-9.2.0/contrib/pg_upgrade/test.sh	2012-09-06 18:13:18.178092176 -0400
@@ -62,10 +62,14 @@
 rm -rf "$logdir"
 mkdir "$logdir"
 
+# we want the Unix sockets in $temp_root
+PGHOST=$temp_root
+export PGHOST
+
 set -x
 
 $oldbindir/initdb
-$oldbindir/pg_ctl start -l "$logdir/postmaster1.log" -w
+$oldbindir/pg_ctl start -l "$logdir/postmaster1.log" -o "-c unix_socket_directories='$PGHOST'" -w
 if "$MAKE" -C "$oldsrc" installcheck; then
 	pg_dumpall -f "$temp_root"/dump1.sql || pg_dumpall1_status=$?
 	if [ "$newsrc" != "$oldsrc" ]; then
@@ -108,7 +112,7 @@
 
 pg_upgrade -d "${PGDATA}.old" -D "${PGDATA}" -b "$oldbindir" -B "$bindir"
 
-pg_ctl start -l "$logdir/postmaster2.log" -w
+pg_ctl start -l "$logdir/postmaster2.log" -o "-c unix_socket_directories='$PGHOST'" -w
 
 if [ $testhost = Msys ] ; then
 	cmd /c analyze_new_cluster.bat
diff -Naur postgresql-9.2.0.sockets/src/backend/utils/misc/guc.c postgresql-9.2.0/src/backend/utils/misc/guc.c
--- postgresql-9.2.0.sockets/src/backend/utils/misc/guc.c	2012-09-06 18:12:36.458693394 -0400
+++ postgresql-9.2.0/src/backend/utils/misc/guc.c	2012-09-06 18:13:18.181092327 -0400
@@ -2901,7 +2901,7 @@
 		},
 		&Unix_socket_directories,
 #ifdef HAVE_UNIX_SOCKETS
-		DEFAULT_PGSOCKET_DIR,
+		DEFAULT_PGSOCKET_DIR ", /tmp",
 #else
 		"",
 #endif
diff -Naur postgresql-9.2.0.sockets/src/bin/initdb/initdb.c postgresql-9.2.0/src/bin/initdb/initdb.c
--- postgresql-9.2.0.sockets/src/bin/initdb/initdb.c	2012-09-06 18:12:36.460693488 -0400
+++ postgresql-9.2.0/src/bin/initdb/initdb.c	2012-09-06 18:13:18.183092471 -0400
@@ -1003,7 +1003,7 @@
 
 #ifdef HAVE_UNIX_SOCKETS
 	snprintf(repltok, sizeof(repltok), "#unix_socket_directories = '%s'",
-			 DEFAULT_PGSOCKET_DIR);
+			 DEFAULT_PGSOCKET_DIR ", /tmp");
 #else
 	snprintf(repltok, sizeof(repltok), "#unix_socket_directories = ''");
 #endif
diff -Naur postgresql-9.2.0.sockets/src/include/pg_config_manual.h postgresql-9.2.0/src/include/pg_config_manual.h
--- postgresql-9.2.0.sockets/src/include/pg_config_manual.h	2012-09-06 17:26:17.000000000 -0400
+++ postgresql-9.2.0/src/include/pg_config_manual.h	2012-09-06 18:13:18.183092471 -0400
@@ -144,7 +144,7 @@
  * here's where to twiddle it.  You can also override this at runtime
  * with the postmaster's -k switch.
  */
-#define DEFAULT_PGSOCKET_DIR  "/tmp"
+#define DEFAULT_PGSOCKET_DIR  "/var/run/postgresql"
 
 /*
  * The random() function is expected to yield values between 0 and
diff -Naur postgresql-9.2.0.sockets/src/test/regress/pg_regress.c postgresql-9.2.0/src/test/regress/pg_regress.c
--- postgresql-9.2.0.sockets/src/test/regress/pg_regress.c	2012-09-06 17:26:17.000000000 -0400
+++ postgresql-9.2.0/src/test/regress/pg_regress.c	2012-09-06 18:13:18.184092537 -0400
@@ -772,7 +772,7 @@
 		if (hostname != NULL)
 			doputenv("PGHOST", hostname);
 		else
-			unsetenv("PGHOST");
+			doputenv("PGHOST", "/tmp");
 		unsetenv("PGHOSTADDR");
 		if (port != -1)
 		{
@@ -2233,7 +2233,7 @@
 		 */
 		header(_("starting postmaster"));
 		snprintf(buf, sizeof(buf),
-				 SYSTEMQUOTE "\"%s/postgres\" -D \"%s/data\" -F%s -c \"listen_addresses=%s\" > \"%s/log/postmaster.log\" 2>&1" SYSTEMQUOTE,
+				 SYSTEMQUOTE "\"%s/postgres\" -D \"%s/data\" -F%s -c \"listen_addresses=%s\" -c \"unix_socket_directories=/tmp\" > \"%s/log/postmaster.log\" 2>&1" SYSTEMQUOTE,
 				 bindir, temp_install,
 				 debug ? " -d 5" : "",
 				 hostname ? hostname : "",