QThread::isFinished should return true from finished()

and isRunning() should return false.

This restore the Qt 4.7 behaviour

In Qt 4.7, the finished() was called with the thread's intenal mutex
locked. Which mean that:
 - Call to isRunning or isFinished called from a slot connected to
   finish within the thread would deadlock. (Hence no compatibility
   to keep here)
 - Call to isRunning or isFinished from a slot connected with
   QueuedConnection in another thread would lock the mutex until
   the destructors are finished. and then return as if the thread have
   finished.

Change-Id: I963eccae8f7634aff90cc4bbab6ca886a78e35eb
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(cherry-picked from qtbase commit ec5e59b73c20a7dc6aec96c829f1e53c3fa58c07)
Task-number: QTBUG-30251
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

2 files changed, 37 insertions, 2 deletions

diff --git a/src/corelib/thread/qthread.cpp b/src/corelib/thread/qthread.cpp
index 53e4d5e..74bbd4e 100644
--- a/src/corelib/thread/qthread.cpp
+++ b/src/corelib/thread/qthread.cpp
@@ -457,7 +457,7 @@ bool QThread::isFinished() const
 {
     Q_D(const QThread);
     QMutexLocker locker(&d->mutex);
-    return d->finished;
+    return d->finished || d->isInFinish;
 }
 
 /*!
@@ -475,7 +475,7 @@ bool QThread::isRunning() const
     if (d->data->symbian_thread_handle.Handle() && d->data->symbian_thread_handle.ExitType() != EExitPending)
         return false;
 #endif
-    return d->running;
+    return d->running && !d->isInFinish;
 }
 
 /*!
diff --git a/tests/auto/qthread/tst_qthread.cpp b/tests/auto/qthread/tst_qthread.cpp
index c56d302..ee9ac30 100644
--- a/tests/auto/qthread/tst_qthread.cpp
+++ b/tests/auto/qthread/tst_qthread.cpp
@@ -117,6 +117,7 @@ private slots:
     void destroyFinishRace();
     void startFinishRace();
     void startAndQuitCustomEventLoop();
+    void isRunningInFinished();
 
     void stressTest();
 #ifdef Q_OS_SYMBIAN
@@ -1418,5 +1419,39 @@ void tst_QThread::threadNameTest()
 }
 #endif // Q_OS_SYMBIAN
 
+class FinishedTestObject : public QObject {
+    Q_OBJECT
+public:
+    FinishedTestObject() : ok(false) {}
+    bool ok;
+public slots:
+    void slotFinished() {
+        QThread *t = qobject_cast<QThread *>(sender());
+        ok = t && t->isFinished() && !t->isRunning();
+    }
+};
+
+void tst_QThread::isRunningInFinished()
+{
+    for (int i = 0; i < 15; i++) {
+        QThread thread;
+        thread.start();
+        FinishedTestObject localObject;
+        FinishedTestObject inThreadObject;
+        localObject.setObjectName("...");
+        inThreadObject.moveToThread(&thread);
+        connect(&thread, SIGNAL(finished()), &localObject, SLOT(slotFinished()));
+        connect(&thread, SIGNAL(finished()), &inThreadObject, SLOT(slotFinished()));
+        QEventLoop loop;
+        connect(&thread, SIGNAL(finished()), &loop, SLOT(quit()));
+        QMetaObject::invokeMethod(&thread, "quit", Qt::QueuedConnection);
+        loop.exec();
+        QVERIFY(!thread.isRunning());
+        QVERIFY(thread.isFinished());
+        QVERIFY(localObject.ok);
+        QVERIFY(inThreadObject.ok);
+    }
+}
+
 QTEST_MAIN(tst_QThread)
 #include "tst_qthread.moc"