Reduce risk of accidentally running temp-install regression tests against

a mismatching installation.  Pick a default port number calculated from the
version number, and try a few times with other numbers if that one doesn't
work.  Check if we can connect to the port before starting our own postmaster,
to detect some other server already running there.  To simplify the code,
drop --temp-port option and use --port for both temp-install and pre-installed
case.

src/test/regress/GNUmakefile

@@ -6,7 +6,7 @@
 # Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
 # Portions Copyright (c) 1994, Regents of the University of California
 #
-# $PostgreSQL: pgsql/src/test/regress/GNUmakefile,v 1.75 2008/10/01 22:38:57 petere Exp $
+# $PostgreSQL: pgsql/src/test/regress/GNUmakefile,v 1.76 2008/11/28 12:45:34 petere Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -14,9 +14,6 @@ subdir = src/test/regress
 top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global
 
-# port number for temp-installation test postmaster
-TEMP_PORT = 5$(DEF_PGPORT)
-
 # file with extra config for temp build
 TEMP_CONF =
 ifdef TEMP_CONFIG
@@ -144,7 +141,7 @@ tablespace-setup:
 pg_regress_call = ./pg_regress --inputdir=$(srcdir) --dlpath=. --multibyte=$(MULTIBYTE) --load-language=plpgsql $(NOLOCALE)
 
 check: all
-	$(pg_regress_call) --temp-install=./tmp_check --top-builddir=$(top_builddir) --temp-port=$(TEMP_PORT) --schedule=$(srcdir)/parallel_schedule $(MAXCONNOPT) $(TEMP_CONF)
+	$(pg_regress_call) --temp-install=./tmp_check --top-builddir=$(top_builddir) --schedule=$(srcdir)/parallel_schedule $(MAXCONNOPT) $(TEMP_CONF)
 
 installcheck: all
 	$(pg_regress_call) --psqldir=$(PSQLDIR) --schedule=$(srcdir)/serial_schedule
@@ -163,7 +160,7 @@ bigtest: all
 	$(pg_regress_call) --psqldir=$(PSQLDIR) --schedule=$(srcdir)/serial_schedule numeric_big 
 
 bigcheck: all
-	$(pg_regress_call) --temp-install=./tmp_check --top-builddir=$(top_builddir) --temp-port=$(TEMP_PORT) --schedule=$(srcdir)/parallel_schedule $(MAXCONNOPT) numeric_big
+	$(pg_regress_call) --temp-install=./tmp_check --top-builddir=$(top_builddir) --schedule=$(srcdir)/parallel_schedule $(MAXCONNOPT) numeric_big
 
 
 ##

src/test/regress/pg_regress.c

@@ -11,7 +11,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/test/regress/pg_regress.c,v 1.53 2008/11/26 13:26:52 tgl Exp $
+ * $PostgreSQL: pgsql/src/test/regress/pg_regress.c,v 1.54 2008/11/28 12:45:34 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -83,10 +83,10 @@ static _stringlist *extra_tests = NULL;
 static char *temp_install = NULL;
 static char *temp_config = NULL;
 static char *top_builddir = NULL;
-static int	temp_port = 65432;
 static bool nolocale = false;
 static char *hostname = NULL;
 static int	port = -1;
+static bool port_specified_by_user = false;
 static char *dlpath = PKGLIBDIR;
 static char *user = NULL;
 static _stringlist *extraroles = NULL;
@@ -1844,7 +1844,7 @@ help(void)
 	printf(_("Options for \"temp-install\" mode:\n"));
 	printf(_("  --no-locale               use C locale\n"));
 	printf(_("  --top-builddir=DIR        (relative) path to top level build directory\n"));
-	printf(_("  --temp-port=PORT          port number to start temp postmaster on\n"));
+	printf(_("  --port=PORT               start postmaster on PORT\n"));
 	printf(_("  --temp-config=PATH        append contents of PATH to temporary config\n"));
 	printf(_("\n"));
 	printf(_("Options for using an existing installation:\n"));
@@ -1867,6 +1867,7 @@ regression_main(int argc, char *argv[], init_function ifunc, test_function tfunc
 	int			i;
 	int			option_index;
 	char		buf[MAXPGPATH * 4];
+	char		buf2[MAXPGPATH * 4];
 
 	static struct option long_options[] = {
 		{"help", no_argument, NULL, 'h'},
@@ -1882,7 +1883,6 @@ regression_main(int argc, char *argv[], init_function ifunc, test_function tfunc
 		{"temp-install", required_argument, NULL, 9},
 		{"no-locale", no_argument, NULL, 10},
 		{"top-builddir", required_argument, NULL, 11},
-		{"temp-port", required_argument, NULL, 12},
 		{"host", required_argument, NULL, 13},
 		{"port", required_argument, NULL, 14},
 		{"user", required_argument, NULL, 15},
@@ -1956,20 +1956,12 @@ regression_main(int argc, char *argv[], init_function ifunc, test_function tfunc
 			case 11:
 				top_builddir = strdup(optarg);
 				break;
-			case 12:
-				{
-					int			p = atoi(optarg);
-
-					/* Since Makefile isn't very bright, check port range */
-					if (p >= 1024 && p <= 65535)
-						temp_port = p;
-				}
-				break;
 			case 13:
 				hostname = strdup(optarg);
 				break;
 			case 14:
 				port = atoi(optarg);
+				port_specified_by_user = true;
 				break;
 			case 15:
 				user = strdup(optarg);
@@ -2005,8 +1997,13 @@ regression_main(int argc, char *argv[], init_function ifunc, test_function tfunc
 		optind++;
 	}
 
-	if (temp_install)
+	if (temp_install && !port_specified_by_user)
-		port = temp_port;
+		/*
+		 * To reduce chances of interference with parallel
+		 * installations, use a port number starting in the private
+		 * range (49152-65535) calculated from the version number.
+		 */
+		port = 0xC000 | (PG_VERSION_NUM & 0x3FFF);
 
 	inputdir = make_absolute_path(inputdir);
 	outputdir = make_absolute_path(outputdir);
@@ -2106,6 +2103,37 @@ regression_main(int argc, char *argv[], init_function ifunc, test_function tfunc
 			fclose(pg_conf);
 		}
 
+		/*
+		 * Check if there is a postmaster running already.
+		 */
+		snprintf(buf2, sizeof(buf2),
+				 SYSTEMQUOTE "\"%s/psql\" -X postgres <%s 2>%s" SYSTEMQUOTE,
+				 bindir, DEVNULL, DEVNULL);
+
+		for (i = 0; i < 16; i++)
+		{
+			if (system(buf2) == 0)
+			{
+				char		s[16];
+
+				if (port_specified_by_user || i == 15)
+				{
+					fprintf(stderr, _("port %d apparently in use\n"), port);
+					if (!port_specified_by_user)
+						fprintf(stderr, _("%s: could not determine an available port\n"), progname);
+					fprintf(stderr, _("Specify an unused port using the --port option or shut down any conflicting PostgreSQL servers.\n"));
+					exit_nicely(2);
+				}
+
+				fprintf(stderr, _("port %d apparently in use, trying %d\n"), port, port+1);
+				port++;
+				sprintf(s, "%d", port);
+				doputenv("PGPORT", s);
+			}
+			else
+				break;
+		}
+
 		/*
 		 * Start the temp postmaster
 		 */
@@ -2129,13 +2157,10 @@ regression_main(int argc, char *argv[], init_function ifunc, test_function tfunc
 		 * second or so, but Cygwin is reportedly *much* slower).  Don't wait
 		 * forever, however.
 		 */
-		snprintf(buf, sizeof(buf),
-				 SYSTEMQUOTE "\"%s/psql\" -X postgres <%s 2>%s" SYSTEMQUOTE,
-				 bindir, DEVNULL, DEVNULL);
 		for (i = 0; i < 60; i++)
 		{
 			/* Done if psql succeeds */
-			if (system(buf) == 0)
+			if (system(buf2) == 0)
 				break;
 
 			/*
@@ -2180,7 +2205,7 @@ regression_main(int argc, char *argv[], init_function ifunc, test_function tfunc
 		postmaster_running = true;
 
 		printf(_("running on port %d with pid %lu\n"),
-			   temp_port, (unsigned long) postmaster_pid);
+			   port, (unsigned long) postmaster_pid);
 	}
 	else
 	{