Created attachment 1741313 [details]
proposed patch

Description of problem:

The ls -t option doesn't sort the globbed files upon the modification time.

sftp> ls -ltr SG*
-rw-r--r--    ? 0        0               0 Dec 22 17:43 SG0003
-rw-r--r--    ? 0        0               0 Dec 22 17:40 SG0001
-rw-r--r--    ? 0        0               0 Dec 22 17:45 SG0002

The root cause is in usage of the timespeccmp macro in sglob_comp().
The timespeccmp macro returns 0 (false) or 1 (true) as the result of comparison with "<". When the -r option is not used, sglob_comp() returns
1 or 0 only. When the -r option is used, it returns -1 or 0 only

sglob_comp(const void *aa, const void *bb)
{
...
        int rmul = sort_flag & LS_REVERSE_SORT ? -1 : 1;
...
        else if (sort_flag & LS_TIME_SORT) {
#if defined(HAVE_STRUCT_STAT_ST_MTIM)
                return (rmul * timespeccmp(&as->st_mtim, &bs->st_mtim, <));


The following is about the comparison function of qsort() in man qsort.

In man qsort
       The comparison function must return an integer less than, equal to, or greater than zero if the first argument is considered to be
       respectively less than, equal to, or greater than the second.  If two members compare as equal, their order in the sorted array is
       undefined.


So, the above sglob_comp() doesn't meet this requirement.
It should return -1, 0, or 1.


Version-Release number of selected component (if applicable):
openssh-8.0p1-5.el8.x86_64

How reproducible:
Always

Steps to Reproduce:
1. Create three files in /root on any ssh server

   # cd /root
   # touch SG0001
   wait more than one minute
   # touch SG0003
   wait more than one minute
   # touch SG0002

NOTE: We can see the difference of the modification time in the "ls -lt" output by waiting more than one minute.

2. connect with sftp from *RHEL8.3 client*

   # sftp root@<hostname>

NOTE: sorting is done in the sftp client side.

3. Run "ls -ltr SG*"

Actual results:
Sorting with -l option doesn't work.

sftp> ls -ltr SG*
-rw-r--r--    ? 0        0               0 Dec 22 17:43 SG0003
-rw-r--r--    ? 0        0               0 Dec 22 17:40 SG0001
-rw-r--r--    ? 0        0               0 Dec 22 17:45 SG0002

Expected results:
Sorting with -l option works.

sftp> ls -ltr SG*
-rw-r--r--    ? 0        0               0 Dec 22 17:40 SG0001
-rw-r--r--    ? 0        0               0 Dec 22 17:43 SG0003
-rw-r--r--    ? 0        0               0 Dec 22 17:45 SG0002