Merge bitcoin#18285: test: Check that wait_until returns if time poin…

…t is in the past

fab7d14 test: Check that wait_until returns if time point is in the past (MarcoFalke)

Pull request description:

  Add an explicit regression test for the condvar bug (bitcoin#18227), so that this doesn't happen again

ACKs for top commit:
  laanwj:
    ACK fab7d14

Tree-SHA512: 6ec0d0b3945cae87a001e367af34cca1953a8082b4a0d9f8a20d30acd1f36363e98035d4eb173ff786cf6692d352d41f960633415c46394af042eb44e3b5ad71

src/test/scheduler_tests.cpp

@@ -112,6 +112,24 @@ BOOST_AUTO_TEST_CASE(manythreads)
     BOOST_CHECK_EQUAL(counterSum, 200);
 }
 
+BOOST_AUTO_TEST_CASE(wait_until_past)
+{
+    std::condition_variable condvar;
+    Mutex mtx;
+    WAIT_LOCK(mtx, lock);
+
+    const auto no_wait= [&](const std::chrono::seconds& d) {
+        return condvar.wait_until(lock, std::chrono::system_clock::now() - d);
+    };
+
+    BOOST_CHECK(std::cv_status::timeout == no_wait(std::chrono::seconds{1}));
+    BOOST_CHECK(std::cv_status::timeout == no_wait(std::chrono::minutes{1}));
+    BOOST_CHECK(std::cv_status::timeout == no_wait(std::chrono::hours{1}));
+    BOOST_CHECK(std::cv_status::timeout == no_wait(std::chrono::hours{10}));
+    BOOST_CHECK(std::cv_status::timeout == no_wait(std::chrono::hours{100}));
+    BOOST_CHECK(std::cv_status::timeout == no_wait(std::chrono::hours{1000}));
+}
+
 BOOST_AUTO_TEST_CASE(singlethreadedscheduler_ordered)
 {
     CScheduler scheduler;