===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/tmux/cmd-pipe-pane.c,v
retrieving revision 1.44
retrieving revision 1.45
diff -u -r1.44 -r1.45
--- src/usr.bin/tmux/cmd-pipe-pane.c	2017/07/12 09:24:17	1.44
+++ src/usr.bin/tmux/cmd-pipe-pane.c	2017/07/12 10:04:51	1.45
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-pipe-pane.c,v 1.44 2017/07/12 09:24:17 nicm Exp $ */
+/* $OpenBSD: cmd-pipe-pane.c,v 1.45 2017/07/12 10:04:51 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -22,6 +22,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <paths.h>
+#include <signal.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
@@ -62,6 +63,7 @@
 	char			*cmd;
 	int			 old_fd, pipe_fd[2], null_fd;
 	struct format_tree	*ft;
+	sigset_t		 set, oldset;
 
 	/* Destroy the old pipe. */
 	old_fd = wp->pipe_fd;
@@ -102,16 +104,20 @@
 	format_free(ft);
 
 	/* Fork the child. */
+	sigfillset(&set);
+	sigprocmask(SIG_BLOCK, &set, &oldset);
 	switch (fork()) {
 	case -1:
+		sigprocmask(SIG_SETMASK, &oldset, NULL);
 		cmdq_error(item, "fork error: %s", strerror(errno));
 
 		free(cmd);
 		return (CMD_RETURN_ERROR);
 	case 0:
 		/* Child process. */
-		close(pipe_fd[0]);
 		proc_clear_signals(server_proc);
+		sigprocmask(SIG_SETMASK, &oldset, NULL);
+		close(pipe_fd[0]);
 
 		if (dup2(pipe_fd[1], STDIN_FILENO) == -1)
 			_exit(1);
@@ -132,6 +138,7 @@
 		_exit(1);
 	default:
 		/* Parent process. */
+		sigprocmask(SIG_SETMASK, &oldset, NULL);
 		close(pipe_fd[1]);
 
 		wp->pipe_fd = pipe_fd[0];