===================================================================
RCS file: /cvs/mandoc/tag.c,v
retrieving revision 1.11
retrieving revision 1.12
diff -u -p -r1.11 -r1.12
--- mandoc/tag.c	2015/11/20 21:59:54	1.11
+++ mandoc/tag.c	2016/07/08 20:42:15	1.12
@@ -1,4 +1,4 @@
-/*      $Id: tag.c,v 1.11 2015/11/20 21:59:54 schwarze Exp $    */
+/*      $Id: tag.c,v 1.12 2016/07/08 20:42:15 schwarze Exp $    */
 /*
  * Copyright (c) 2015 Ingo Schwarze <schwarze@openbsd.org>
  *
@@ -57,6 +57,24 @@ tag_init(void)
 	tag_files.tfd = -1;
 	tag_files.tcpgid = -1;
 
+	/* Clean up when dying from a signal. */
+
+	memset(&sa, 0, sizeof(sa));
+	sigfillset(&sa.sa_mask);
+	sa.sa_handler = tag_signal;
+	sigaction(SIGHUP, &sa, NULL);
+	sigaction(SIGINT, &sa, NULL);
+	sigaction(SIGTERM, &sa, NULL);
+
+	/*
+	 * POSIX requires that a process calling tcsetpgrp(3)
+	 * from the background gets a SIGTTOU signal.
+	 * In that case, do not stop.
+	 */
+
+	sa.sa_handler = SIG_IGN;
+	sigaction(SIGTTOU, &sa, NULL);
+
 	/* Save the original standard output for use by the pager. */
 
 	if ((tag_files.ofd = dup(STDOUT_FILENO)) == -1)
@@ -68,12 +86,6 @@ tag_init(void)
 	    sizeof(tag_files.ofn));
 	(void)strlcpy(tag_files.tfn, "/tmp/man.XXXXXXXXXX",
 	    sizeof(tag_files.tfn));
-	memset(&sa, 0, sizeof(sa));
-	sigfillset(&sa.sa_mask);
-	sa.sa_handler = tag_signal;
-	sigaction(SIGHUP, &sa, NULL);
-	sigaction(SIGINT, &sa, NULL);
-	sigaction(SIGTERM, &sa, NULL);
 	if ((ofd = mkstemp(tag_files.ofn)) == -1)
 		goto fail;
 	if ((tag_files.tfd = mkstemp(tag_files.tfn)) == -1)