When the user exits the pager before the pager has drained all input

from man(1), man(1) dies from SIGPIPE.  Exiting man(1) is fine in this
case, generating more output would be pointless, but without handling
SIGPIPE, the exit code from man(1) was wrong and csh(1) printed an
ugly message "Broken pipe".  Fix this by handling SIGPIPE explicitly.
Issue noticed by deraadt@.

2 files changed, 16 insertions, 3 deletions

diff --git a/main.c b/main.c
index f0cd8ca0..eb5a54eb 100644
--- a/main.c
+++ b/main.c
@@ -1,4 +1,4 @@
-/*	$Id: main.c,v 1.225 2015/03/10 13:50:03 schwarze Exp $ */
+/*	$Id: main.c,v 1.226 2015/03/17 07:33:07 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2012, 2014, 2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -27,6 +27,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <glob.h>
+#include <signal.h>
 #include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
@@ -92,6 +93,7 @@ static	int		  fs_lookup(const struct manpaths *,
 static	void		  fs_search(const struct mansearch *,
 				const struct manpaths *, int, char**,
 				struct manpage **, size_t *);
+static	void		  handle_sigpipe(int);
 static	int		  koptions(int *, char *);
 #if HAVE_SQLITE3
 int			  mandocdb(int, char**);
@@ -111,6 +113,7 @@ static	const int sec_prios[] = {1, 4, 5, 8, 6, 3, 7, 2, 9};
 static	char		  help_arg[] = "help";
 static	char		 *help_argv[] = {help_arg, NULL};
 static	const char	 *progname;
+static	enum mandoclevel  rc;
 
 
 int
@@ -127,7 +130,7 @@ main(int argc, char *argv[])
 	size_t		 isec, i, sz;
 	int		 prio, best_prio, synopsis_only;
 	char		 sec;
-	enum mandoclevel rc, rctmp;
+	enum mandoclevel rctmp;
 	enum outmode	 outmode;
 	int		 fd;
 	int		 show_usage;
@@ -940,6 +943,13 @@ mmsg(enum mandocerr t, enum mandoclevel lvl,
 	fputc('\n', stderr);
 }
 
+static void
+handle_sigpipe(int signum)
+{
+
+	exit(rc);
+}
+
 static pid_t
 spawn_pager(void)
 {
@@ -972,6 +982,7 @@ spawn_pager(void)
 			exit((int)MANDOCLEVEL_SYSERR);
 		}
 		close(fildes[1]);
+		signal(SIGPIPE, handle_sigpipe);
 		return(pager_pid);
 	}
 
diff --git a/read.c b/read.c
index 471d4150..397e6cd7 100644
--- a/read.c
+++ b/read.c
@@ -1,4 +1,4 @@
-/*	$Id: read.c,v 1.131 2015/03/11 13:05:20 schwarze Exp $ */
+/*	$Id: read.c,v 1.132 2015/03/17 07:33:07 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -29,6 +29,7 @@
 #include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <signal.h>
 #include <stdarg.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -846,6 +847,7 @@ mparse_open(struct mparse *curp, int *fd, const char *file)
 			perror("dup");
 			exit((int)MANDOCLEVEL_SYSERR);
 		}
+		signal(SIGPIPE, SIG_DFL);
 		execlp("gunzip", "gunzip", "-c", file, NULL);
 		perror("exec");
 		exit((int)MANDOCLEVEL_SYSERR);