Re: Tab completion regression test failed on illumos

On Thu, 02 Nov 2023 at 22:23, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Japin Li <japinli(at)hotmail(dot)com> writes:
>> It seems the 'SEL\t' is converted to 'SEL ' which is "SEL" with 5 spaces.
>
> That would be plausible if readline were disabled, or otherwise
> not functioning.
>

I think this might be a bug comes from Illumos pseudo-tty. I can reproduce
this by using pseudo-tty on Illumos.

Here is a simple test case:

$ cat pseudo-tty.c
#define _XOPEN_SOURCE 600

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/wait.h>

#define DEV_PTMX "/dev/ptmx"

int
main(void)
{
int ptm_fd;
pid_t pid;
char *pts_name;

ptm_fd = open(DEV_PTMX, O_RDWR);
grantpt(ptm_fd);
unlockpt(ptm_fd);
pts_name = ptsname(ptm_fd);

pid = fork();
if (pid == -1) {
fprintf(stderr, "could not fork a new process: %m\n");
close(ptm_fd);
return -1;
} else if (pid == 0) {
int pts_fd;

close(ptm_fd);
pts_fd = open(pts_name, O_RDWR);
write(pts_fd, "SEL\tH", 5);
close(pts_fd);
} else {
int status;
char buffer[512] = { 0 };
ssize_t bytes;

bytes = read(ptm_fd, buffer, sizeof(buffer));
printf("%ld: '%s'\n", bytes, buffer);
waitpid(pid, &status, 0);
close(ptm_fd);
}

return 0;
}

On IllumsOS
$ gcc -o pseudo-tty pseudo-tty.c
$ ./pseudo-tty
9: 'SEL H'

On Ubuntu
$ gcc -o pseudo-tty pseudo-tty.c
$ ./pseudo-tty
5: 'SEL H'

--
Regrads,
Japin Li
ChengDu WenWu Information Technology Co., Ltd.