Clear machine id with null context restore

- As passing in null context don't have any
  meaning other than doing reset with pre-defined
  behaviour which currently just resets back to
  initial state and clears extended state variables.
  Now Also clearing machine id back to null which is
  anyway a default value.
- Backport #381
- Relates #307

spring-statemachine-core/src/main/java/org/springframework/statemachine/state/AbstractState.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 the original author or authors.
+ * Copyright 2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -198,17 +198,13 @@ public abstract class AbstractState<S, E> extends LifecycleObjectSupport impleme
 	public void exit(StateContext<S, E> context) {
 		cancelStateActions();
 		stateListener.onExit(context);
-		for (Trigger<S, E> trigger : triggers) {
-			trigger.disarm();
-		}
+		disarmTriggers();
 	}
 
 	@Override
 	public void entry(StateContext<S, E> context) {
 		stateListener.onEntry(context);
-		for (Trigger<S, E> trigger : triggers) {
-			trigger.arm();
-		}
+		armTriggers();
 		scheduleStateActions(context);
 	}
 
@@ -292,6 +288,16 @@ public abstract class AbstractState<S, E> extends LifecycleObjectSupport impleme
 		}
 	}
 
+	@Override
+	protected void doStart() {
+		armTriggers();
+	}
+
+	@Override
+	protected void doStop() {
+		disarmTriggers();
+	}
+
 	/**
 	 * Gets the submachine.
 	 *
@@ -332,6 +338,24 @@ public abstract class AbstractState<S, E> extends LifecycleObjectSupport impleme
 		return triggers;
 	}
 
+	/**
+	 * Arm triggers.
+	 */
+	protected void armTriggers() {
+		for (Trigger<S, E> trigger : triggers) {
+			trigger.arm();
+		}
+	}
+
+	/**
+	 * Disarm triggers.
+	 */
+	protected void disarmTriggers() {
+		for (Trigger<S, E> trigger : triggers) {
+			trigger.disarm();
+		}
+	}
+
 	/**
 	 * Cancel existing state actions and clear list.
 	 */

spring-statemachine-core/src/main/java/org/springframework/statemachine/support/AbstractStateMachine.java

@@ -20,6 +20,7 @@ import org.apache.commons.logging.LogFactory;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanFactoryAware;
+import org.springframework.context.Lifecycle;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageHeaders;
 import org.springframework.messaging.support.MessageBuilder;
@@ -727,6 +728,9 @@ public abstract class AbstractStateMachine<S, E> extends StateMachineObjectSuppo
 		if (stateSet && stateMachineContext.getExtendedState() != null) {
 			this.extendedState = stateMachineContext.getExtendedState();
 		}
+		if (currentState instanceof Lifecycle) {
+			((Lifecycle)currentState).start();
+		}
 	}
 
 	@Override

spring-statemachine-core/src/test/java/org/springframework/statemachine/StateMachineResetTests.java

@@ -33,7 +33,9 @@ import org.springframework.statemachine.access.StateMachineAccess;
 import org.springframework.statemachine.access.StateMachineFunction;
 import org.springframework.statemachine.action.Action;
 import org.springframework.statemachine.config.EnableStateMachine;
+import org.springframework.statemachine.config.EnableStateMachineFactory;
 import org.springframework.statemachine.config.EnumStateMachineConfigurerAdapter;
+import org.springframework.statemachine.config.StateMachineFactory;
 import org.springframework.statemachine.config.builders.StateMachineConfigurationConfigurer;
 import org.springframework.statemachine.config.builders.StateMachineStateConfigurer;
 import org.springframework.statemachine.config.builders.StateMachineTransitionConfigurer;
@@ -251,6 +253,31 @@ public class StateMachineResetTests extends AbstractStateMachineTests {
 		assertThat(machine.getExtendedState().getVariables().size(), is(0));
 	}
 
+	@Test
+	public void testRestoreWithTimer() throws Exception {
+		context.register(Config4.class);
+		context.refresh();
+		@SuppressWarnings("unchecked")
+		StateMachineFactory<States, Events> factory = context.getBean(StateMachineSystemConstants.DEFAULT_ID_STATEMACHINEFACTORY,
+				StateMachineFactory.class);
+		StateMachine<States, Events> machine = factory.getStateMachine();
+
+		DefaultStateMachineContext<States, Events> stateMachineContext = new DefaultStateMachineContext<States, Events>(States.S1, null,
+				null, null);
+		machine.getStateMachineAccessor().doWithAllRegions(new StateMachineFunction<StateMachineAccess<States,Events>>() {
+
+			@Override
+			public void apply(StateMachineAccess<States, Events> function) {
+				function.resetStateMachine(stateMachineContext);
+			}
+		});
+
+		machine.start();
+		Thread.sleep(1100);
+		assertThat(machine.getState().getIds(), containsInAnyOrder(States.S2));
+
+	}
+
 	@Configuration
 	@EnableStateMachine
 	static class Config1 extends EnumStateMachineConfigurerAdapter<States, Events> {
@@ -420,6 +447,36 @@ public class StateMachineResetTests extends AbstractStateMachineTests {
 
 	}
 
+	@Configuration
+	@EnableStateMachineFactory
+	static class Config4 extends EnumStateMachineConfigurerAdapter<States, Events> {
+
+		@Override
+		public void configure(StateMachineStateConfigurer<States, Events> states)
+				throws Exception {
+			states
+				.withStates()
+					.initial(States.S0)
+					.state(States.S1)
+					.state(States.S2);
+		}
+
+		@Override
+		public void configure(StateMachineTransitionConfigurer<States, Events> transitions)
+				throws Exception {
+			transitions
+				.withExternal()
+					.source(States.S0)
+					.target(States.S1)
+					.event(Events.A)
+					.and()
+				.withExternal()
+					.source(States.S1)
+					.target(States.S2)
+					.timerOnce(1000);
+		}
+	}
+
 	public static enum States {
 		S0, S1, S11, S12, S2, S21, S211, S212
 	}