1 files changed, 26 insertions, 2 deletions
diff --git a/src/zeroconf/avahi/Poll.cxx b/src/zeroconf/avahi/Poll.cxx
index 0cec88f17..1d0f39895 100644
--- a/src/zeroconf/avahi/Poll.cxx
+++ b/src/zeroconf/avahi/Poll.cxx
@@ -89,13 +89,13 @@ public:
 		:event(_loop, BIND_THIS_METHOD(OnTimeout)),
 		 callback(_callback), userdata(_userdata) {
 		if (tv != nullptr)
-			event.Schedule(ToSteadyClockDuration(*tv));
+			Schedule(*tv);
 	}
 
 	static void TimeoutUpdate(AvahiTimeout *t,
 				  const struct timeval *tv) noexcept {
 		if (tv != nullptr)
-			t->event.Schedule(ToSteadyClockDuration(*tv));
+			t->Schedule(*tv);
 		else
 			t->event.Cancel();
 	}
@@ -105,6 +105,30 @@ public:
 	}
 
 private:
+	[[gnu::pure]]
+	Event::Duration AbsoluteToDuration(const struct timeval &tv) noexcept {
+		if (tv.tv_sec == 0)
+			/* schedule immediately */
+			return {};
+
+		struct timeval now;
+		if (gettimeofday(&now, nullptr) < 0)
+			/* shouldn't ever fail, but if it does, do
+			   something reasonable */
+			return std::chrono::seconds(1);
+
+		auto d = ToSteadyClockDuration(tv)
+			- ToSteadyClockDuration(now);
+		if (d.count() < 0)
+			return {};
+
+		return d;
+	}
+
+	void Schedule(const struct timeval &tv) noexcept {
+		event.Schedule(AbsoluteToDuration(tv));
+	}
+
 	void OnTimeout() noexcept {
 		callback(this, userdata);
 	}