fix usage of locks with vfork

[musl] / src / process / posix_spawn_file_actions_adddup2.c

#include <spawn.h>
#include <stdlib.h>
#include <errno.h>
#include "fdop.h"

int posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *fa, int fd, int newfd)
{
        struct fdop *op = malloc(sizeof *op);
        if (!op) return ENOMEM;
        op->cmd = FDOP_DUP2;
        op->fd = fd;
        op->newfd = newfd;
        if ((op->next = fa->__actions)) op->next->prev = op;
        op->prev = 0;
        fa->__actions = op;
        return 0;
}