diff: Correct fd 0 case on pipe

After git commit c8d40bf8ec, if fd 0 was
not open, it is left with CLOEXEC set and therefore fails. This is an
unlikely situation, but fixing it reduces the size of the code (by using
posix_spawn_file_actions_adddup2's special case if the two file
descriptor numbers are the same).

At the same time, check the error code from
posix_spawn_file_actions_adddup2.

Reviewed by:	bapt
Differential Revision:	https://reviews.freebsd.org/D56910

This commit is contained in:

Jilles Tjoelker

2026-06-03 22:42:01 +02:00

parent 248dd56d2d

commit 8bf4902569

1 changed files with 3 additions and 2 deletions

									
										usr.bin/diff/pr.c
									
		+3
		-2
	
												View File
												
				@@ -71,8 +71,9 @@ start_pr(char *file1, char *file2)

					posix_spawnattr_setprocdescp_np(&sa, &pr->procd, 0);

					if (pfd[0] != STDIN_FILENO)

						posix_spawn_file_actions_adddup2(&fa, pfd[0], STDIN_FILENO);

					error = posix_spawn_file_actions_adddup2(&fa, pfd[0], STDIN_FILENO);

					if (error != 0)

						errc(2, error, "posix_spawn_file_actions_adddup2");

					char *argv[] = { __DECONST(char *, _PATH_PR),

					    __DECONST(char *, "-h"), header, NULL };