fix: removing invalid timers.

- Removing invalid timers should do nothing.

Author: kcexn

include/net/timers/impl/timers_impl.hpp

@@ -144,7 +144,8 @@ auto timers<Interrupt>::remove(timer_id tid) noexcept -> void
 {
   // The timer id will be added to the free_ids list once
   // the event propagates out of the eventq.
-  state_.events[tid].armed.clear();
+  if (tid < state_.events.size())
+    state_.events[tid].armed.clear();
 }
 
 /**

tests/test_timers.cpp

@@ -67,6 +67,9 @@ TEST(TimersTests, TimerAdd)
 TEST(TimersTests, ReuseTimerID)
 {
   auto timers = timers_type();
+
+  timers.remove(INVALID_TIMER); // Make sure this doesn't break.
+
   auto timer0 = timers.add(100, [](timer_id) {});
   ASSERT_EQ(timer0, 0);
   timers.remove(timer0);