krb5 commit [krb5-1.21]: Fix krb5_crypto_us_timeofday() microseconds check

https://github.com/krb5/krb5/commit/7910ea9a7e5a1c9ed4c973c862e2bd96fea0fd13
commit 7910ea9a7e5a1c9ed4c973c862e2bd96fea0fd13
Author: Alexey Tikhonov <[email protected]>
Date:   Thu Oct 3 18:40:04 2024 +0200

    Fix krb5_crypto_us_timeofday() microseconds check
    
    Commit a60db180211a383bd382afe729e9309acb8dcf53 mistakenly reversed
    the sense of the krb5_crypto_us_timeofday() conditional that enforces
    fowards movement of the microseconds value within a second.  Moreover,
    the macros ts_after() and ts_incr() should not have been applied to
    non-timestamp values.  Revert the incorrect changes.
    
    [[email protected]: rewrote commit message]
    
    (cherry picked from commit 6f6d795be8d0dd0a46952cf8afa59b65d71df744)
    
    ticket: 9141
    version_fixed: 1.21.4

 src/lib/krb5/os/c_ustime.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/lib/krb5/os/c_ustime.c b/src/lib/krb5/os/c_ustime.c
index f69f2ea4c..7019ea197 100644
--- a/src/lib/krb5/os/c_ustime.c
+++ b/src/lib/krb5/os/c_ustime.c
@@ -106,14 +106,14 @@ krb5_crypto_us_timeofday(krb5_timestamp *seconds, krb5_int32 *microseconds)
        need to properly handle the case where the administrator intentionally
        adjusted time backwards. */
     if (now.sec == ts_incr(last_time.sec, -1) ||
-        (now.sec == last_time.sec && !ts_after(last_time.usec, now.usec))) {
+        (now.sec == last_time.sec && now.usec <= last_time.usec)) {
         /* Correct 'now' to be exactly one microsecond later than 'last_time'.
            Note that _because_ we perform this hack, 'now' may be _earlier_
            than 'last_time', even though the system time is monotonically
            increasing. */
 
         now.sec = last_time.sec;
-        now.usec = ts_incr(last_time.usec, 1);
+        now.usec = last_time.usec + 1;
         if (now.usec >= 1000000) {
             now.sec = ts_incr(now.sec, 1);
             now.usec = 0;