WinRT: Don't use the native thread handle for waiting

There is no guarantee that the handle from std::thread will be valid
when a wait is made. Instead, simply use an elapsed timer and check
if the thread is finished. This prevents an exception from being thrown
when a bad handle is encountered.

Task-number: QTBUG-31397
Change-Id: Ie2a7e6cbfbb27bf1baff779322670d85e92e10dd
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>

src/corelib/thread/qthread_win.cpp

@@ -63,6 +63,7 @@
 #include <qt_windows.h>
 
 #ifdef Q_OS_WINRT
+#include <qelapsedtimer.h>
 #include <thread>
 #endif
 
@@ -680,21 +681,11 @@ bool QThread::wait(unsigned long time)
         break;
     }
 #else // !Q_OS_WINRT
-    if (d->handle->joinable()) {
-        HANDLE handle = d->handle->native_handle();
-        switch (WaitForSingleObjectEx(handle, time, FALSE)) {
-        case WAIT_OBJECT_0:
-            ret = true;
-            d->handle->join();
-            break;
-        case WAIT_FAILED:
-            qErrnoWarning("QThread::wait: WaitForSingleObjectEx() failed");
-            break;
-        case WAIT_ABANDONED:
-        case WAIT_TIMEOUT:
-        default:
-            break;
-        }
+    if (!d->finished) {
+        QElapsedTimer timer;
+        timer.start();
+        while (timer.elapsed() < time && !d->finished)
+            yieldCurrentThread();
     }
 #endif // Q_OS_WINRT