QScxmlStateMachine add runtime warning

As suggested by Ulf, in addition to correcting the documentation
runtime warning will be helpful. This commit adds the warning
and a test for that

Change-Id: I6dbd727e493431d7d71efbc5b527df8d67d50dcd
Fixes: QTBUG-109371
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

3 files changed, 26 insertions, 0 deletions

diff --git a/src/scxml/qscxmlstatemachine.cpp b/src/scxml/qscxmlstatemachine.cpp
index 71d35b3..04d3726 100644
--- a/src/scxml/qscxmlstatemachine.cpp
+++ b/src/scxml/qscxmlstatemachine.cpp
@@ -2262,12 +2262,18 @@ QBindable<QList<QScxmlInvokableService*>> QScxmlStateMachine::bindableInvokedSer
   \note Calling start() after stop() will not result in a full reset of its
   configuration yet, hence it is strongly advised not to do it.
 
+  \note Starting a finished machine yields a warning.
+
   \sa runningChanged(), setRunning(), stop(), finished()
 */
 void QScxmlStateMachine::start()
 {
     Q_D(QScxmlStateMachine);
 
+    if (d->isFinished()) {
+        qCWarning(qscxmlLog) << this << "Can't start finished machine";
+    }
+
     if (!parseErrors().isEmpty())
         return;
 
diff --git a/src/scxml/qscxmlstatemachine_p.h b/src/scxml/qscxmlstatemachine_p.h
index 35fab46..3d18ffc 100644
--- a/src/scxml/qscxmlstatemachine_p.h
+++ b/src/scxml/qscxmlstatemachine_p.h
@@ -391,6 +391,7 @@ private:
     }
 
     bool isPaused() const { return m_runningState == Paused; }
+    bool isFinished() const { return m_runningState == Finished; }
 
     QScxmlInternal::StateMachineInfoProxy *m_infoSignalProxy;
 
diff --git a/tests/auto/statemachine/tst_statemachine.cpp b/tests/auto/statemachine/tst_statemachine.cpp
index 85d06c8..1aa74f7 100644
--- a/tests/auto/statemachine/tst_statemachine.cpp
+++ b/tests/auto/statemachine/tst_statemachine.cpp
@@ -31,6 +31,7 @@ private Q_SLOTS:
 
     void doneDotStateEvent();
     void running();
+    void restart();
 
     void invokeStateMachine();
 
@@ -392,6 +393,24 @@ void tst_StateMachine::running()
     QCOMPARE(stateMachine->isRunning(), false);
 }
 
+void tst_StateMachine::restart()
+{
+    QScopedPointer<QScxmlStateMachine> stateMachine(
+            QScxmlStateMachine::fromFile(QString(":/tst_statemachine/stateDotDoneEvent.scxml")));
+    QVERIFY(!stateMachine.isNull());
+
+    QSignalSpy finishedSpy(stateMachine.data(), SIGNAL(finished()));
+
+    stateMachine->start();
+    finishedSpy.wait(5000);
+    QCOMPARE(finishedSpy.size(), 1);
+    QCOMPARE(stateMachine->activeStateNames(true).size(), 1);
+    QVERIFY(stateMachine->activeStateNames(true).contains(QLatin1String("success")));
+
+    QTest::ignoreMessage(QtWarningMsg, QRegularExpression("(.*)Can't start finished machine"));
+    stateMachine->start();
+}
+
 void tst_StateMachine::invokeStateMachine()
 {
     QScopedPointer<QScxmlStateMachine> stateMachine(