From 16002d174cdd3f6b4fc5b791e17cfdbe04771327 Mon Sep 17 00:00:00 2001
From: Keith Donald <kdonald@vmware.com>
Date: Fri, 13 Mar 2009 20:43:46 +0000
Subject: [PATCH] swf-1057

---
 .../model/builder/DefaultFlowModelHolder.java | 19 ++++++++++++-------
 .../model/builder/FlowModelBuilder.java       | 13 ++++++-------
 2 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/spring-webflow/src/main/java/org/springframework/webflow/engine/model/builder/DefaultFlowModelHolder.java b/spring-webflow/src/main/java/org/springframework/webflow/engine/model/builder/DefaultFlowModelHolder.java
index f03480ba..d776dac3 100644
--- a/spring-webflow/src/main/java/org/springframework/webflow/engine/model/builder/DefaultFlowModelHolder.java
+++ b/spring-webflow/src/main/java/org/springframework/webflow/engine/model/builder/DefaultFlowModelHolder.java
@@ -36,16 +36,12 @@ import org.springframework.webflow.engine.model.registry.FlowModelHolder;
  */
 public class DefaultFlowModelHolder implements FlowModelHolder {
 
-	/**
-	 * The flow model assembled by this assembler.
-	 */
 	private FlowModel flowModel;
 
-	/**
-	 * The flow model builder.
-	 */
 	private FlowModelBuilder flowModelBuilder;
 
+	private boolean assembling;
+
 	/**
 	 * Creates a new refreshable flow model holder that uses the configured assembler (GOF director) to drive flow
 	 * assembly, on initial use and on any resource change or refresh.
@@ -57,6 +53,10 @@ public class DefaultFlowModelHolder implements FlowModelHolder {
 	}
 
 	public synchronized FlowModel getFlowModel() {
+		if (assembling) {
+			// must return early assembly result for when a flow calls itself recursively
+			return flowModelBuilder.getFlowModel();
+		}
 		if (flowModel == null) {
 			assembleFlowModel();
 		} else {
@@ -83,11 +83,16 @@ public class DefaultFlowModelHolder implements FlowModelHolder {
 
 	private void assembleFlowModel() throws FlowModelBuilderException {
 		try {
+			assembling = true;
 			flowModelBuilder.init();
 			flowModelBuilder.build();
 			flowModel = flowModelBuilder.getFlowModel();
 		} finally {
-			flowModelBuilder.dispose();
+			try {
+				flowModelBuilder.dispose();
+			} finally {
+				assembling = false;
+			}
 		}
 	}
 
diff --git a/spring-webflow/src/main/java/org/springframework/webflow/engine/model/builder/FlowModelBuilder.java b/spring-webflow/src/main/java/org/springframework/webflow/engine/model/builder/FlowModelBuilder.java
index 5d0a3e28..11dafda9 100644
--- a/spring-webflow/src/main/java/org/springframework/webflow/engine/model/builder/FlowModelBuilder.java
+++ b/spring-webflow/src/main/java/org/springframework/webflow/engine/model/builder/FlowModelBuilder.java
@@ -21,11 +21,10 @@ import org.springframework.webflow.engine.model.FlowModel;
 /**
  * Builder interface used to build a flow model. The process of building a flow model consists of the following steps:
  * <ol>
- * <li> Initialize this builder by calling {@link #init()}.
- * <li> Call {@link #build()} to create the flow model.
- * <li> Call {@link #getFlowModel()} to return the fully-built {@link FlowModel} model.
- * <li> Dispose this builder, releasing any resources allocated during the building process by calling
- * {@link #dispose()}.
+ * <li>Initialize this builder by calling {@link #init()}.
+ * <li>Call {@link #build()} to create the flow model.
+ * <li>Call {@link #getFlowModel()} to return the fully-built {@link FlowModel} model.
+ * <li>Dispose this builder, releasing any resources allocated during the building process by calling {@link #dispose()}.
  * </ol>
  * <p>
  * Implementations should encapsulate flow construction logic, either for a specific kind of flow, for example, an
@@ -77,8 +76,8 @@ public interface FlowModelBuilder {
 	public Resource getFlowModelResource();
 
 	/**
-	 * Returns true if the underlying flow model resource has changed since the last call to {@link #init()}.
-	 * Always returns false if the flow model is not build from a resource.
+	 * Returns true if the underlying flow model resource has changed since the last call to {@link #init()}. Always
+	 * returns false if the flow model is not build from a resource.
 	 * @return true if the resource backing the flow model has changed
 	 */
 	public boolean hasFlowModelResourceChanged();