Merge aeaeeb0d24 into edc49209f1

The only clock change that affects monotonic timers is suspend causing
CLOCK_MONOTONIC to fall behind CLOCK_BOOTTIME. However, monotonic timers
that use CLOCK_BOOTTIME are not intended to have their elapse time
changed after a suspend. Hence condition the calculation of monotonic
timers’ elapse times on the cause not being a clock change.

Fixes #29245

src/core/timer.c

@@ -476,7 +476,8 @@ static void timer_enter_waiting(Timer *t, bool time_change) {
                                 assert_not_reached();
                         }
 
-                        v->next_elapse = usec_add(usec_shift_clock(base, CLOCK_MONOTONIC, TIMER_MONOTONIC_CLOCK(t)), v->value);
+                        if (!time_change)
+                                v->next_elapse = usec_add(usec_shift_clock(base, CLOCK_MONOTONIC, TIMER_MONOTONIC_CLOCK(t)), v->value);
 
                         if (dual_timestamp_is_set(&t->last_trigger) &&
                             !time_change &&