Fix a regression caused in rev. 1.118, reported by kristaps@:

When using a pager and the first manual shown is gzip'ed,
the gunzip(1) process ended up as a child of the pager process
such that the man(1) process couldn't wait for it, preventing
proper display of the manual.

Solve this by making the pager a child of the man(1) process
(instead of the other way round), which requires being a bit
more careful about properly closing file descriptors after use
and waiting for the pager before exiting man(1).

1 files changed, 22 insertions, 4 deletions

diff --git a/usr.bin/mandoc/main.c b/usr.bin/mandoc/main.c
index d79e6cb8eb3..fd62433c6fd 100644
--- a/usr.bin/mandoc/main.c
+++ b/usr.bin/mandoc/main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: main.c,v 1.128 2015/03/09 21:30:27 schwarze Exp $ */
+/*	$OpenBSD: main.c,v 1.129 2015/03/10 03:00:48 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2012, 2014, 2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -19,6 +19,7 @@
 
 #include <sys/types.h>
 #include <sys/param.h>	/* MACHINE */
+#include <sys/wait.h>
 
 #include <assert.h>
 #include <ctype.h>
@@ -458,6 +459,21 @@ out:
 
 	free(defos);
 
+	/*
+	 * Flush the output and signal end of file.
+	 * If a pager is attached, it allows browsing to the end.
+	 * Otherwise, it does no harm, we are about to exit anyway.
+	 */
+
+	fclose(stdout);
+
+	/*
+	 * If we spawned a pager, wait for the user to close it.
+	 * Otherwise, this call fails with no adverse effect.
+	 */
+
+	wait(NULL);
+
 	return((int)rc);
 }
 
@@ -926,18 +942,19 @@ spawn_pager(void)
 		    progname, strerror(errno));
 		exit((int)MANDOCLEVEL_SYSERR);
 	case 0:
+		break;
+	default:
 		close(fildes[0]);
 		if (dup2(fildes[1], STDOUT_FILENO) == -1) {
 			fprintf(stderr, "%s: dup output: %s\n",
 			    progname, strerror(errno));
 			exit((int)MANDOCLEVEL_SYSERR);
 		}
+		close(fildes[1]);
 		return;
-	default:
-		break;
 	}
 
-	/* The original process becomes the pager. */
+	/* The child process becomes the pager. */
 
 	close(fildes[1]);
 	if (dup2(fildes[0], STDIN_FILENO) == -1) {
@@ -945,6 +962,7 @@ spawn_pager(void)
 		    progname, strerror(errno));
 		exit((int)MANDOCLEVEL_SYSERR);
 	}
+	close(fildes[0]);
 
 	pager = getenv("MANPAGER");
 	if (pager == NULL || *pager == '\0')