All values of tv_sec are valid for absolute timeouts.

ok?

Index: rthread_cond.c
===================================================================
RCS file: /cvs/src/lib/libc/thread/rthread_cond.c,v
diff -u -p -r1.5 rthread_cond.c
--- rthread_cond.c	29 Jan 2019 17:40:26 -0000	1.5
+++ rthread_cond.c	8 Jan 2024 00:55:09 -0000
@@ -142,8 +142,7 @@ pthread_cond_timedwait(pthread_cond_t *c
 	}
 
 	cond = *condp;
-	if (abs == NULL || abs->tv_sec < 0 || abs->tv_nsec < 0 ||
-	    abs->tv_nsec >= 1000000000)
+	if (abs == NULL || abs->tv_nsec < 0 || abs->tv_nsec >= 1000000000)
 		return (EINVAL);
 
 	return (_rthread_cond_timedwait(cond, mutexp, abs));
Index: rthread_sync.c
===================================================================
RCS file: /cvs/src/lib/libc/thread/rthread_sync.c,v
diff -u -p -r1.5 rthread_sync.c
--- rthread_sync.c	24 Apr 2018 16:28:42 -0000	1.5
+++ rthread_sync.c	8 Jan 2024 00:55:09 -0000
@@ -317,7 +317,7 @@ pthread_cond_timedwait(pthread_cond_t *c
 			abort();
 	}
 
-	if (abstime == NULL || abstime->tv_sec < 0 || abstime->tv_nsec < 0 ||
+	if (abstime == NULL || abstime->tv_nsec < 0 ||
 	    abstime->tv_nsec >= 1000000000)
 		return (EINVAL);