From a8194b48e2b988ab140f7ab06ab6a735eacf0830 Mon Sep 17 00:00:00 2001
From: Ben Hale <bhale@vmware.com>
Date: Wed, 15 Aug 2007 17:47:27 +0000
Subject: [PATCH] FORWARD MERGE: SWF-347

---
 spring-webflow/changelog.txt                  |  5 ++-
 .../impl/RequestControlContextImpl.java       | 31 ++++++++++---------
 .../webflow/test/MockRequestContext.java      |  4 +--
 3 files changed, 22 insertions(+), 18 deletions(-)

diff --git a/spring-webflow/changelog.txt b/spring-webflow/changelog.txt
index eaba990c..bf9806ae 100644
--- a/spring-webflow/changelog.txt
+++ b/spring-webflow/changelog.txt
@@ -1,6 +1,6 @@
 SPRING WEB FLOW (SWF) CHANGELOG
 ===============================
-http://www.springframework.org
+http://www.springframework.org/webflow
 
 Changes in version 1.1.0 ()
 -------------------------------------
@@ -9,6 +9,7 @@ Package org.springframework.binding
 * Fixed serializability problems in ConversionException, EvaluationException and MethodInvocationException.
 * Added targetCollection(String) method to MappingBuilder.
 * ConversionExecutor now checks for assignment compatible types (SWF-337).
+* Fixed bug in MapAccessor where accessing a map entry with a null value would result in an exception (SWF-343).
 
 Package org.springframework.webflow.action
 * Improved FormAction.setupForm() JavaDoc (SWF-325).
@@ -44,9 +45,11 @@ Package org.springframework.webflow.engine
   methods to XmlFlowBuilder to allow for control over the registration of beans needed locally by a flow definition.
   Useful for testing (SWF-307).
 * Ensures that all exceptions (including RuntimeExceptions) are handled properly by the FlowExecution (SWF-333).
+* Ensured the RequestContext attribute map can never be null (SWF-347).
 
 Package org.springframework.webflow.execution
 * Added a holder for the FlowExecutionContext of a request (SWF-163).
+* Made the Event class non-final to allow for extension (SWF-330).
 
 Package org.springframework.webflow.executor
 * JSF integration code now manages flow execution locks properly in exceptional situations and when the
diff --git a/spring-webflow/src/main/java/org/springframework/webflow/engine/impl/RequestControlContextImpl.java b/spring-webflow/src/main/java/org/springframework/webflow/engine/impl/RequestControlContextImpl.java
index d3b39003..3abd79dd 100644
--- a/spring-webflow/src/main/java/org/springframework/webflow/engine/impl/RequestControlContextImpl.java
+++ b/spring-webflow/src/main/java/org/springframework/webflow/engine/impl/RequestControlContextImpl.java
@@ -55,35 +55,36 @@ class RequestControlContextImpl implements RequestControlContext {
 	private static final Log logger = LogFactory.getLog(RequestControlContextImpl.class);
 
 	/**
-	 * The owning flow execution.
+	 * The owning flow execution carrying out this request.
 	 */
 	private FlowExecutionImpl flowExecution;
 
-	/**
-	 * The request scope data map.
-	 */
-	private LocalAttributeMap requestScope = new LocalAttributeMap();
-
 	/**
 	 * A source context for the caller who initiated this request.
 	 */
 	private ExternalContext externalContext;
 
 	/**
-	 * The last event that occured in this request context.
+	 * The request scope data map. Never null, initially empty.
+	 */
+	private LocalAttributeMap requestScope = new LocalAttributeMap();
+
+	/**
+	 * Holder for contextual properties describing the currently executing request; never null, initially empty and
+	 * immutable.
+	 */
+	private AttributeMap attributes = CollectionUtils.EMPTY_ATTRIBUTE_MAP;
+
+	/**
+	 * The last event that occurred in this request context; initially null.
 	 */
 	private Event lastEvent;
 
 	/**
-	 * The last transition that executed in this request context.
+	 * The last transition that executed in this request context; initially null.
 	 */
 	private Transition lastTransition;
 
-	/**
-	 * Holder for contextual execution properties.
-	 */
-	private AttributeMap attributes;
-
 	/**
 	 * Create a new request context.
 	 * @param flowExecution the owning flow execution
@@ -91,8 +92,8 @@ class RequestControlContextImpl implements RequestControlContext {
 	 */
 	public RequestControlContextImpl(FlowExecutionImpl flowExecution, ExternalContext externalContext) {
 		Assert.notNull(flowExecution, "The owning flow execution is required");
-		this.externalContext = externalContext;
 		this.flowExecution = flowExecution;
+		this.externalContext = externalContext;
 	}
 
 	// implementing RequestContext
@@ -224,7 +225,7 @@ class RequestControlContextImpl implements RequestControlContext {
 	// internal helpers
 
 	/**
-	 * Returns the execution listerns for the flow execution of this request context.
+	 * Returns the execution listeners for the flow execution of this request context.
 	 */
 	protected FlowExecutionListeners getExecutionListeners() {
 		return flowExecution.getListeners();
diff --git a/spring-webflow/src/main/java/org/springframework/webflow/test/MockRequestContext.java b/spring-webflow/src/main/java/org/springframework/webflow/test/MockRequestContext.java
index 28d9f6ba..a6cf2b9a 100644
--- a/spring-webflow/src/main/java/org/springframework/webflow/test/MockRequestContext.java
+++ b/spring-webflow/src/main/java/org/springframework/webflow/test/MockRequestContext.java
@@ -48,12 +48,12 @@ public class MockRequestContext implements RequestContext {
 
 	private MutableAttributeMap requestScope = new LocalAttributeMap();
 
+	private MutableAttributeMap attributes = new LocalAttributeMap();
+
 	private Event lastEvent;
 
 	private Transition lastTransition;
 
-	private MutableAttributeMap attributes = new LocalAttributeMap();
-
 	/**
 	 * Creates a new mock request context with the following defaults:
 	 * <ul>