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-9.1.4.sockets/contrib/pg_upgrade/server.c postgresql-9.1.4/contrib/pg_upgrade/server.c
--- postgresql-9.1.4.sockets/contrib/pg_upgrade/server.c	2012-05-31 19:07:09.000000000 -0400
+++ postgresql-9.1.4/contrib/pg_upgrade/server.c	2012-08-12 22:43:10.388873678 -0400
@@ -179,11 +179,14 @@
 	 */
 	snprintf(cmd, sizeof(cmd),
 			 SYSTEMQUOTE "\"%s/pg_ctl\" -w -l \"%s\" -D \"%s\" "
-			 "-o \"-p %d %s\" start >> \"%s\" 2>&1" SYSTEMQUOTE,
+			 "-o \"-p %d %s %s\" start >> \"%s\" 2>&1" SYSTEMQUOTE,
 			 cluster->bindir, output_filename, cluster->pgdata, cluster->port,
 			 (cluster->controldata.cat_ver >=
 			  BINARY_UPGRADE_SERVER_FLAG_CAT_VER) ? "-b" :
 			 "-c autovacuum=off -c autovacuum_freeze_max_age=2000000000",
+			 /* assume 9.1 builds will have newer socket directory */
+			 (GET_MAJOR_VERSION(cluster->major_version) < 901) ?
+			 "-c unix_socket_directory=/var/run/postgresql" : "",
 			 output_filename);
 
 	/*
diff -Naur postgresql-9.1.4.sockets/src/backend/utils/misc/guc.c postgresql-9.1.4/src/backend/utils/misc/guc.c
--- postgresql-9.1.4.sockets/src/backend/utils/misc/guc.c	2012-08-12 20:35:22.559682963 -0400
+++ postgresql-9.1.4/src/backend/utils/misc/guc.c	2012-08-12 20:35:55.071983609 -0400
@@ -2874,7 +2874,7 @@
 		},
 		&Unix_socket_directories,
 #ifdef HAVE_UNIX_SOCKETS
-		DEFAULT_PGSOCKET_DIR,
+		DEFAULT_PGSOCKET_DIR ", /tmp",
 #else
 		"",
 #endif
diff -Naur postgresql-9.1.4.sockets/src/bin/initdb/initdb.c postgresql-9.1.4/src/bin/initdb/initdb.c
--- postgresql-9.1.4.sockets/src/bin/initdb/initdb.c	2012-08-12 20:35:22.561682693 -0400
+++ postgresql-9.1.4/src/bin/initdb/initdb.c	2012-08-12 20:35:55.073983799 -0400
@@ -970,7 +970,7 @@
 
 #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-9.1.4.sockets/src/include/pg_config_manual.h postgresql-9.1.4/src/include/pg_config_manual.h
--- postgresql-9.1.4.sockets/src/include/pg_config_manual.h	2012-05-31 19:07:09.000000000 -0400
+++ postgresql-9.1.4/src/include/pg_config_manual.h	2012-08-12 20:35:55.073983799 -0400
@@ -141,7 +141,7 @@
  * 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-9.1.4.sockets/src/test/regress/pg_regress.c postgresql-9.1.4/src/test/regress/pg_regress.c
--- postgresql-9.1.4.sockets/src/test/regress/pg_regress.c	2012-05-31 19:07:09.000000000 -0400
+++ postgresql-9.1.4/src/test/regress/pg_regress.c	2012-08-12 20:38:43.933609334 -0400
@@ -781,7 +781,7 @@
 		if (hostname != NULL)
 			doputenv("PGHOST", hostname);
 		else
-			unsetenv("PGHOST");
+			doputenv("PGHOST", "/tmp");
 		unsetenv("PGHOSTADDR");
 		if (port != -1)
 		{
@@ -2240,7 +2240,7 @@
 		 */
 		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 : "",