1 files changed, 21 insertions, 3 deletions
diff --git a/tests/auto/declarative/qperformancetimer/tst_qperformancetimer.cpp b/tests/auto/declarative/qperformancetimer/tst_qperformancetimer.cpp
index 28dd95ba..958fb1a2 100644
--- a/tests/auto/declarative/qperformancetimer/tst_qperformancetimer.cpp
+++ b/tests/auto/declarative/qperformancetimer/tst_qperformancetimer.cpp
@@ -58,9 +58,27 @@ void tst_qperformancetimer::units()
 {
     QPerformanceTimer timer;
     timer.start();
-    QTest::qWait(300);
-    qint64 elapsed = timer.elapsed();
-    QVERIFY(elapsed > 300000000 && elapsed < 310000000);
+    {
+        QTest::qWait(300);
+        qint64 elapsed = timer.elapsed();
+        QVERIFY(elapsed > 300000000 && elapsed < 310000000);
+    }
+    {
+        qint64 monotonic_time_in_far_future = 1000000000 * 60 * 60 * 24 * 365 * 10; /// 10 years uptime
+        qint64 elapsed = timer.elapsedToAbsoluteTime(time_in_far_future);
+        elapsed = elapsed - timer.elapsedToAbsoluteTime(time_in_far_future - 2000000);
+        QVERIFY(elapsed == 2000000);
+    }
+    {
+        qint64 elapsed = timer.elapsed();
+        qint64 elapsed2 = timer.elapsedToAbsoluteTime(elapsed);
+        qint64 monotonic_now = 2 * elapsed - elapsed2;
+        QTest::qWait(300);
+        elapsed = timer.elapsed();
+        elapsed2 = timer.elapsedToAbsoluteTime(monotonic_now + 300 * 1000000);
+        qint64 diff = elapsed - elapsed2;
+        QVERIFY(diff > -10000000 && diff < 10000000);
+    }
 }
 
 QTEST_MAIN(tst_qperformancetimer)