pg_upgrade test chatter

diff --git a/src/test/regress/pg_regress.c b/src/test/regress/pg_regress.c
index 05296f7ee1..cfadc0cd70 100644
--- a/src/test/regress/pg_regress.c
+++ b/src/test/regress/pg_regress.c
@@ -122,7 +122,9 @@ static void make_directory(const char *dir);
 
 static void header(const char *fmt,...) pg_attribute_printf(1, 2);
 static void status(const char *fmt,...) pg_attribute_printf(1, 2);
-static void psql_command(const char *database, const char *query,...) pg_attribute_printf(2, 3);
+static StringInfo psql_start_command(void);
+static void psql_add_command(StringInfo buf, const char *query,...) pg_attribute_printf(2, 3);
+static void psql_end_command(StringInfo buf, const char *database);
 
 /*
  * allow core files if possible.
@@ -1136,51 +1138,94 @@ config_sspi_auth(const char *pgdata, const char *superuser_name)
 #endif							/* ENABLE_SSPI */
 
 /*
- * Issue a command via psql, connecting to the specified database
+ * psql_start_command, psql_add_command, psql_end_command
+ *
+ * Issue one or more commands within one psql call.
+ * Set up with psql_start_command, then add commands one at a time
+ * with psql_add_command, and finally execute with psql_end_command.
  *
  * Since we use system(), this doesn't return until the operation finishes
  */
+static StringInfo
+psql_start_command(void)
+{
+	StringInfo	buf = makeStringInfo();
+
+	appendStringInfo(buf,
+					 "\"%s%spsql\" -X",
+					 bindir ? bindir : "",
+					 bindir ? "/" : "");
+	return buf;
+}
+
 static void
-psql_command(const char *database, const char *query,...)
+psql_add_command(StringInfo buf, const char *query,...)
 {
-	char		query_formatted[1024];
-	char		query_escaped[2048];
-	char		psql_cmd[MAXPGPATH + 2048];
-	va_list		args;
-	char	   *s;
-	char	   *d;
+	StringInfoData cmdbuf;
+	const char *cmdptr;
+
+	/* Add each command as a -c argument in the psql call */
+	appendStringInfoString(buf, " -c \"");
 
 	/* Generate the query with insertion of sprintf arguments */
-	va_start(args, query);
-	vsnprintf(query_formatted, sizeof(query_formatted), query, args);
-	va_end(args);
+	initStringInfo(&cmdbuf);
+	for (;;)
+	{
+		va_list		args;
+		int			needed;
+
+		va_start(args, query);
+		needed = appendStringInfoVA(&cmdbuf, query, args);
+		va_end(args);
+		if (needed == 0)
+			break;				/* success */
+		enlargeStringInfo(&cmdbuf, needed);
+	}
 
 	/* Now escape any shell double-quote metacharacters */
-	d = query_escaped;
-	for (s = query_formatted; *s; s++)
+	for (cmdptr = cmdbuf.data; *cmdptr; cmdptr++)
 	{
-		if (strchr("\\\"$`", *s))
-			*d++ = '\\';
-		*d++ = *s;
+		if (strchr("\\\"$`", *cmdptr))
+			appendStringInfoChar(buf, '\\');
+		appendStringInfoChar(buf, *cmdptr);
 	}
-	*d = '\0';
 
-	/* And now we can build and execute the shell command */
-	snprintf(psql_cmd, sizeof(psql_cmd),
-			 "\"%s%spsql\" -X -c \"%s\" \"%s\"",
-			 bindir ? bindir : "",
-			 bindir ? "/" : "",
-			 query_escaped,
-			 database);
+	appendStringInfoChar(buf, '"');
+
+	pfree(cmdbuf.data);
+}
 
-	if (system(psql_cmd) != 0)
+static void
+psql_end_command(StringInfo buf, const char *database)
+{
+	/* Add the database name --- assume it needs no extra escaping */
+	appendStringInfo(buf,
+					 " \"%s\"",
+					 database);
+
+	/* And now we can execute the shell command */
+	if (system(buf->data) != 0)
 	{
 		/* psql probably already reported the error */
-		fprintf(stderr, _("command failed: %s\n"), psql_cmd);
+		fprintf(stderr, _("command failed: %s\n"), buf->data);
 		exit(2);
 	}
+
+	/* Clean up */
+	pfree(buf->data);
+	pfree(buf);
 }
 
+/*
+ * Shorthand macro for the common case of a single command
+ */
+#define psql_command(database, ...) \
+	do { \
+		StringInfo buf = psql_start_command(); \
+		psql_add_command(buf, __VA_ARGS__); \
+		psql_end_command(buf, database); \
+	} while (0)
+
 /*
  * Spawn a process to execute the given shell command; don't wait for it
  *
@@ -2012,8 +2057,13 @@ open_result_files(void)
 static void
 drop_database_if_exists(const char *dbname)
 {
+	StringInfo	buf = psql_start_command();
+
 	header(_("dropping database \"%s\""), dbname);
-	psql_command("postgres", "DROP DATABASE IF EXISTS \"%s\"", dbname);
+	/* Set warning level so we don't see chatter about nonexistent DB */
+	psql_add_command(buf, "SET client_min_messages = warning");
+	psql_add_command(buf, "DROP DATABASE IF EXISTS \"%s\"", dbname);
+	psql_end_command(buf, "postgres");
 }
 
 static void
@@ -2055,8 +2105,13 @@ create_database(const char *dbname)
 static void
 drop_role_if_exists(const char *rolename)
 {
+	StringInfo	buf = psql_start_command();
+
 	header(_("dropping role \"%s\""), rolename);
-	psql_command("postgres", "DROP ROLE IF EXISTS \"%s\"", rolename);
+	/* Set warning level so we don't see chatter about nonexistent role */
+	psql_add_command(buf, "SET client_min_messages = warning");
+	psql_add_command(buf, "DROP ROLE IF EXISTS \"%s\"", rolename);
+	psql_end_command(buf, "postgres");
 }
 
 static void