We can keep track of the pager PID without additional complexity.

No functional change for now, but more robust in case anybody should
ever add additional child processes.

1 files changed, 23 insertions, 27 deletions

diff --git a/usr.bin/mandoc/main.c b/usr.bin/mandoc/main.c
index fd62433c6fd..876dfaad1d0 100644
--- a/usr.bin/mandoc/main.c
+++ b/usr.bin/mandoc/main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: main.c,v 1.129 2015/03/10 03:00:48 schwarze Exp $ */
+/*	$OpenBSD: main.c,v 1.130 2015/03/10 13:48:57 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2012, 2014, 2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -93,7 +93,7 @@ static	void		  mmsg(enum mandocerr, enum mandoclevel,
 static	void		  parse(struct curparse *, int,
 				const char *, enum mandoclevel *);
 static	enum mandoclevel  passthrough(const char *, int, int);
-static	void		  spawn_pager(void);
+static	pid_t		  spawn_pager(void);
 static	int		  toptions(struct curparse *, char *);
 static	void		  usage(enum argmode) __attribute__((noreturn));
 static	int		  woptions(struct curparse *, char *);
@@ -122,9 +122,9 @@ main(int argc, char *argv[])
 	enum outmode	 outmode;
 	int		 fd;
 	int		 show_usage;
-	int		 use_pager;
 	int		 options;
 	int		 c;
+	pid_t		 pager_pid;  /* 0: don't use; 1: not yet spawned. */
 
 	if (argc < 1)
 		progname = "mandoc";
@@ -165,7 +165,7 @@ main(int argc, char *argv[])
 	options = MPARSE_SO | MPARSE_UTF8 | MPARSE_LATIN1;
 	defos = NULL;
 
-	use_pager = 1;
+	pager_pid = 1;
 	show_usage = 0;
 	synopsis_only = 0;
 	outmode = OUTMODE_DEF;
@@ -180,7 +180,7 @@ main(int argc, char *argv[])
 			conf_file = optarg;
 			break;
 		case 'c':
-			use_pager = 0;
+			pager_pid = 0;
 			break;
 		case 'f':
 			search.argmode = ARG_WORD;
@@ -188,7 +188,7 @@ main(int argc, char *argv[])
 		case 'h':
 			(void)strlcat(curp.outopts, "synopsis,", BUFSIZ);
 			synopsis_only = 1;
-			use_pager = 0;
+			pager_pid = 0;
 			outmode = OUTMODE_ALL;
 			break;
 		case 'I':
@@ -263,7 +263,7 @@ main(int argc, char *argv[])
 		switch (search.argmode) {
 		case ARG_FILE:
 			outmode = OUTMODE_ALL;
-			use_pager = 0;
+			pager_pid = 0;
 			break;
 		case ARG_NAME:
 			outmode = OUTMODE_ONE;
@@ -397,8 +397,8 @@ main(int argc, char *argv[])
 		mparse_keep(curp.mp);
 
 	if (argc < 1) {
-		if (use_pager && isatty(STDOUT_FILENO))
-			spawn_pager();
+		if (pager_pid == 1 && isatty(STDOUT_FILENO))
+			pager_pid = spawn_pager();
 		parse(&curp, STDIN_FILENO, "<stdin>", &rc);
 	}
 
@@ -409,9 +409,8 @@ main(int argc, char *argv[])
 			rc = rctmp;
 
 		if (fd != -1) {
-			if (use_pager && isatty(STDOUT_FILENO))
-				spawn_pager();
-			use_pager = 0;
+			if (pager_pid == 1 && isatty(STDOUT_FILENO))
+				pager_pid = spawn_pager();
 
 			if (resp == NULL)
 				parse(&curp, fd, *argv, &rc);
@@ -460,19 +459,15 @@ 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.
+	 * If a pager is attached, flush the pipe leading to it
+	 * and signal end of file such that the user can browse
+	 * to the end.  Then wait for the user to close the pager.
 	 */
 
-	fclose(stdout);
-
-	/*
-	 * If we spawned a pager, wait for the user to close it.
-	 * Otherwise, this call fails with no adverse effect.
-	 */
-
-	wait(NULL);
+	if (pager_pid != 0 && pager_pid != 1) {
+		fclose(stdout);
+		waitpid(pager_pid, NULL, 0);
+	}
 
 	return((int)rc);
 }
@@ -920,7 +915,7 @@ mmsg(enum mandocerr t, enum mandoclevel lvl,
 	fputc('\n', stderr);
 }
 
-static void
+static pid_t
 spawn_pager(void)
 {
 #define MAX_PAGER_ARGS 16
@@ -929,14 +924,15 @@ spawn_pager(void)
 	char		*cp;
 	int		 fildes[2];
 	int		 argc;
+	pid_t		 pager_pid;
 
 	if (pipe(fildes) == -1) {
 		fprintf(stderr, "%s: pipe: %s\n",
 		    progname, strerror(errno));
-		return;
+		return(0);
 	}
 
-	switch (fork()) {
+	switch (pager_pid = fork()) {
 	case -1:
 		fprintf(stderr, "%s: fork: %s\n",
 		    progname, strerror(errno));
@@ -951,7 +947,7 @@ spawn_pager(void)
 			exit((int)MANDOCLEVEL_SYSERR);
 		}
 		close(fildes[1]);
-		return;
+		return(pager_pid);
 	}
 
 	/* The child process becomes the pager. */