Use stdout rather than stdin for controlling the terminal

such that "cat foo.mdoc | man -l" works.
Issue reported by Christian Neukirchen <chneukirchen at gmail dot com>
and also tested by him on Void Linux with both glibc and musl.
The patch makes sense to millert@.

1 files changed, 5 insertions, 5 deletions

diff --git a/main.c b/main.c
index c3e6f766..84533fcd 100644
--- a/main.c
+++ b/main.c
@@ -531,10 +531,10 @@ out:
 
 			/* Stop here until moved to the foreground. */
 
-			tc_pgid = tcgetpgrp(STDIN_FILENO);
+			tc_pgid = tcgetpgrp(tag_files->ofd);
 			if (tc_pgid != man_pgid) {
 				if (tc_pgid == pager_pid) {
-					(void)tcsetpgrp(STDIN_FILENO,
+					(void)tcsetpgrp(tag_files->ofd,
 					    man_pgid);
 					if (signum == SIGTTIN)
 						continue;
@@ -547,7 +547,7 @@ out:
 			/* Once in the foreground, activate the pager. */
 
 			if (pager_pid) {
-				(void)tcsetpgrp(STDIN_FILENO, pager_pid);
+				(void)tcsetpgrp(tag_files->ofd, pager_pid);
 				kill(pager_pid, SIGCONT);
 			} else
 				pager_pid = spawn_pager(tag_files);
@@ -1076,7 +1076,7 @@ spawn_pager(struct tag_files *tag_files)
 		break;
 	default:
 		(void)setpgid(pager_pid, 0);
-		(void)tcsetpgrp(STDIN_FILENO, pager_pid);
+		(void)tcsetpgrp(tag_files->ofd, pager_pid);
 #if HAVE_PLEDGE
 		if (pledge("stdio rpath tmppath tty proc", NULL) == -1)
 			err((int)MANDOCLEVEL_SYSERR, "pledge");
@@ -1094,7 +1094,7 @@ spawn_pager(struct tag_files *tag_files)
 
 	/* Do not start the pager before controlling the terminal. */
 
-	while (tcgetpgrp(STDIN_FILENO) != getpid())
+	while (tcgetpgrp(STDOUT_FILENO) != getpid())
 		nanosleep(&timeout, NULL);
 
 	execvp(argv[0], argv);