Fix integer overflows in QDeadlineTimer

If the deadline is far in the future, the conversions to nanoseconds
or internal arithmetic may overflow and give an invalid object, thus
the deadline may end up in the past. Added a test to the testlib
selftest for sleep.

[ChangeLog][QtCore][QDeadlineTimer] Fixed integer overflows
leading to immediate timeouts.

Task-number: QTBUG-69750
Change-Id: I9814eccdf9f9b3add9ca66ec3e27e10cd5ad54a8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/tests/auto/testlib/selftests/sleep/tst_sleep.cpp b/tests/auto/testlib/selftests/sleep/tst_sleep.cpp
index afe6e22120..b7b141afd0 100644
--- a/tests/auto/testlib/selftests/sleep/tst_sleep.cpp
+++ b/tests/auto/testlib/selftests/sleep/tst_sleep.cpp
@@ -36,6 +36,7 @@ class tst_Sleep: public QObject
 
 private slots:
     void sleep();
+    void wait();
 };
 
 void tst_Sleep::sleep()
@@ -53,6 +54,24 @@ void tst_Sleep::sleep()
     QVERIFY(t.elapsed() > 1000 * 10);
 }
 
+void tst_Sleep::wait()
+{
+    QElapsedTimer t;
+    t.start();
+
+    QTest::qWait(1);
+    QVERIFY(t.elapsed() >= 1);
+
+    QTest::qWait(10);
+    QVERIFY(t.elapsed() >= 11);
+
+    QTest::qWait(100);
+    QVERIFY(t.elapsed() >= 111);
+
+    QTest::qWait(1000);
+    QVERIFY(t.elapsed() >= 1111);
+}
+
 QTEST_MAIN(tst_Sleep)
 
 #include "tst_sleep.moc"