statemachine: Emit finished() signal when the initial state is final

It's legal to set a QFinalState as the initial state. The state
machine should correctly emit the finished() signal upon entering
such a state in the initial transition, and don't do any further
processing.

Change-Id: Ica8d3fadbbde604512ea1136624af54eb3b13b11
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@nokia.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/src/corelib/statemachine/qstatemachine.cpp b/src/corelib/statemachine/qstatemachine.cpp
index f1ca421de2..6412d7a0a9 100644
--- a/src/corelib/statemachine/qstatemachine.cpp
+++ b/src/corelib/statemachine/qstatemachine.cpp
@@ -1341,6 +1341,9 @@ void QStateMachinePrivate::_q_start()
 #ifndef QT_NO_ANIMATION
     QList<QAbstractAnimation*> selectedAnimations = selectAnimations(transitions);
 #endif
+    // enterStates() will set stopProcessingReason to Finished if a final
+    // state is entered.
+    stopProcessingReason = EventQueueEmpty;
     enterStates(&nullEvent, exitedStates, enteredStates, statesForDefaultEntry,
                 assignmentsForEnteredStates
 #ifndef QT_NO_ANIMATION
@@ -1355,7 +1358,15 @@ void QStateMachinePrivate::_q_start()
 
     emit q->started();
 
-    _q_process();
+    if (stopProcessingReason == Finished) {
+        // The state machine immediately reached a final state.
+        processingScheduled = false;
+        state = NotRunning;
+        unregisterAllTransitions();
+        emit q->finished();
+    } else {
+        _q_process();
+    }
 }
 
 void QStateMachinePrivate::_q_process()