Upgraded to 5.10-SNAPSHOT and applied patch ACT-1156 thanks Capacia

modules/activiti-cactus/pom.xml

@@ -12,7 +12,7 @@
     <groupId>org.activiti</groupId>
     <artifactId>activiti-root</artifactId>
     <relativePath>../..</relativePath>
-    <version>5.9-SNAPSHOT</version>
+    <version>5.10-SNAPSHOT</version>
   </parent>
 
   <dependencies>

modules/activiti-camel/pom.xml

@@ -12,7 +12,7 @@
 		<groupId>org.activiti</groupId>
 		<artifactId>activiti-root</artifactId>
 		<relativePath>../..</relativePath>
-        <version>5.9-SNAPSHOT</version>
+        <version>5.10-SNAPSHOT</version>
 	</parent>
 
 

modules/activiti-cdi/pom.xml

@@ -12,7 +12,7 @@
 		<groupId>org.activiti</groupId>
 		<artifactId>activiti-root</artifactId>
 		<relativePath>../..</relativePath>
-		<version>5.9-SNAPSHOT</version>
+		<version>5.10-SNAPSHOT</version>
 	</parent>
 
 	<dependencies>

modules/activiti-cxf/pom.xml

@@ -11,7 +11,7 @@
 		<groupId>org.activiti</groupId>
 		<artifactId>activiti-root</artifactId>
 		<relativePath>../..</relativePath>
-		<version>5.9-SNAPSHOT</version>
+		<version>5.10-SNAPSHOT</version>
 
 	</parent>
 

modules/activiti-engine/pom.xml

@@ -11,7 +11,7 @@
     <groupId>org.activiti</groupId>
     <artifactId>activiti-root</artifactId>
     <relativePath>../..</relativePath>
-    <version>5.9-SNAPSHOT</version>
+    <version>5.10-SNAPSHOT</version>
   </parent>
 
   <dependencies>

modules/activiti-engine/src/main/java/org/activiti/engine/impl/bpmn/behavior/CallActivityBehavior.java

@@ -58,7 +58,7 @@ public class CallActivityBehavior extends AbstractBpmnActivityBehavior implement
 
   public void execute(ActivityExecution execution) throws Exception {
     
-    if ((processDefinitonKey == null) && (processDefinitionExpression != null)) {
+    if (processDefinitionExpression != null) {
       processDefinitonKey = (String) processDefinitionExpression.getValue(execution);
     }
     

modules/activiti-engine/src/test/java/org/activiti/engine/test/bpmn/callactivity/CallActivityAdvancedTest.java

@@ -138,6 +138,65 @@ public class CallActivityAdvancedTest extends PluggableActivitiTestCase {
     taskService.complete(taskB.getId());
     assertEquals(0, runtimeService.createExecutionQuery().count());
   }
+
+  @Deployment(resources = { "org/activiti/engine/test/bpmn/callactivity/CallActivity.testCallSequentialSubProcess.bpmn20.xml",
+		  "org/activiti/engine/test/bpmn/callactivity/CallActivity.testCallSimpleSubProcessWithExpressions.bpmn20.xml",
+		  "org/activiti/engine/test/bpmn/callactivity/simpleSubProcess.bpmn20.xml",
+  	      "org/activiti/engine/test/bpmn/callactivity/simpleSubProcess2.bpmn20.xml"})
+  public void testCallSequentialSubProcessWithExpressions() {
+
+	    ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("callSequentialSubProcess");
+
+	    // FIRST sub process calls simpleSubProcess
+	    
+	    // one task in the subprocess should be active after starting the process
+	    // instance
+	    TaskQuery taskQuery = taskService.createTaskQuery();
+	    Task taskBeforeSubProcess = taskQuery.singleResult();
+	    assertEquals("Task before subprocess", taskBeforeSubProcess.getName());
+
+	    // Completing the task continues the process which leads to calling the
+	    // subprocess. The sub process we want to call is passed in as a variable
+	    // into this task
+	    taskService.setVariable(taskBeforeSubProcess.getId(), "simpleSubProcessExpression", "simpleSubProcess");
+	    taskService.complete(taskBeforeSubProcess.getId());
+	    Task taskInSubProcess = taskQuery.singleResult();
+	    assertEquals("Task in subprocess", taskInSubProcess.getName());
+
+	    // Completing the task in the subprocess, finishes the subprocess
+	    taskService.complete(taskInSubProcess.getId());
+	    Task taskAfterSubProcess = taskQuery.singleResult();
+	    assertEquals("Task after subprocess", taskAfterSubProcess.getName());
+
+	    // Completing this task end the process instance
+	    taskService.complete(taskAfterSubProcess.getId());
+	    
+	    
+	    // SECOND sub process calls simpleSubProcess2
+	    
+	    // one task in the subprocess should be active after starting the process
+	    // instance
+	    taskQuery = taskService.createTaskQuery();
+	    taskBeforeSubProcess = taskQuery.singleResult();
+	    assertEquals("Task before subprocess", taskBeforeSubProcess.getName());
+
+	    // Completing the task continues the process which leads to calling the
+	    // subprocess. The sub process we want to call is passed in as a variable
+	    // into this task
+	    taskService.setVariable(taskBeforeSubProcess.getId(), "simpleSubProcessExpression", "simpleSubProcess2");
+	    taskService.complete(taskBeforeSubProcess.getId());
+	    taskInSubProcess = taskQuery.singleResult();
+	    assertEquals("Task in subprocess 2", taskInSubProcess.getName());
+
+	    // Completing the task in the subprocess, finishes the subprocess
+	    taskService.complete(taskInSubProcess.getId());
+	    taskAfterSubProcess = taskQuery.singleResult();
+	    assertEquals("Task after subprocess", taskAfterSubProcess.getName());
+
+	    // Completing this task end the process instance
+	    taskService.complete(taskAfterSubProcess.getId());
+	    assertProcessEnded(processInstance.getId());
+  }
   
   @Deployment(resources = {
     "org/activiti/engine/test/bpmn/callactivity/CallActivity.testTimerOnCallActivity.bpmn20.xml",

modules/activiti-engine/src/test/resources/org/activiti/engine/test/bpmn/callactivity/CallActivity.testCallSequentialSubProcess.bpmn20.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<definitions id="definitions" 
+  xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
+  xmlns:activiti="http://activiti.org/bpmn"
+  targetNamespace="Examples">
+  
+  <process id="callSequentialSubProcess">
+  
+    <startEvent id="theStart" />
+    
+    <sequenceFlow id="flow1" sourceRef="theStart" targetRef="callSubProcess" />
+    
+    <callActivity id="callSubProcess" name="" calledElement="callSimpleSubProcess">
+      <multiInstanceLoopCharacteristics isSequential="true">
+        <loopCardinality>2</loopCardinality>
+      </multiInstanceLoopCharacteristics>
+    </callActivity>
+    
+    <sequenceFlow id="flow3" sourceRef="callSubProcess" targetRef="theEnd" />
+    
+    <endEvent id="theEnd" />
+    
+  </process>
+
+</definitions>

modules/activiti-engine/src/test/resources/org/activiti/engine/test/bpmn/callactivity/simpleSubProcess2.bpmn20.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<definitions id="definitions" 
+  xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
+  xmlns:activiti="http://activiti.org/bpmn"
+  targetNamespace="Examples">
+  
+  <process id="simpleSubProcess2">
+  
+    <startEvent id="theStart" />
+    
+    <sequenceFlow id="flow1" sourceRef="theStart" targetRef="task" />
+  
+    <userTask id="task" name="Task in subprocess 2" />
+    
+    <sequenceFlow id="flow2" sourceRef="task" targetRef="theEnd" />
+    
+    <endEvent id="theEnd" />
+    
+  </process>
+
+</definitions>
\ No newline at end of file

modules/activiti-mule/pom.xml

@@ -11,7 +11,7 @@
 		<groupId>org.activiti</groupId>
 		<artifactId>activiti-root</artifactId>
 		<relativePath>../..</relativePath>
-		<version>5.9-SNAPSHOT</version>
+		<version>5.10-SNAPSHOT</version>
 
 	</parent>
 

modules/activiti-osgi/pom.xml

@@ -12,7 +12,7 @@
 		<groupId>org.activiti</groupId>
 		<artifactId>activiti-root</artifactId>
 		<relativePath>../..</relativePath>
-        <version>5.9-SNAPSHOT</version>
+        <version>5.10-SNAPSHOT</version>
 	</parent>
 
 	<build>

modules/activiti-spring/pom.xml

@@ -10,7 +10,7 @@
 		<groupId>org.activiti</groupId>
 		<artifactId>activiti-root</artifactId>
 		<relativePath>../..</relativePath>
-		<version>5.9-SNAPSHOT</version>
+		<version>5.10-SNAPSHOT</version>
 	</parent>
 
 	<dependencies>

modules/activiti-upgrade/pom.xml

@@ -6,7 +6,7 @@
   <name>Activiti - Upgrade</name>
   <groupId>org.activiti</groupId>
   <artifactId>activiti-upgrade</artifactId>
-  <version>5.9-ALWAYS-SNAPSHOT</version>
+  <version>5.10-ALWAYS-SNAPSHOT</version>
 
   <properties>
     <skipTests>true</skipTests>

modules/activiti-webapp-explorer2/pom.xml

@@ -12,7 +12,7 @@
     <groupId>org.activiti</groupId>
     <artifactId>activiti-root</artifactId>
     <relativePath>../..</relativePath>
-    <version>5.9-SNAPSHOT</version>
+    <version>5.10-SNAPSHOT</version>
   </parent>
 
   <properties>

modules/activiti-webapp-rest2/pom.xml

@@ -10,7 +10,7 @@
     <groupId>org.activiti</groupId>
     <artifactId>activiti-root</artifactId>
     <relativePath>../..</relativePath>
-    <version>5.9-SNAPSHOT</version>
+    <version>5.10-SNAPSHOT</version>
   </parent>
 
 	<build>

pom.xml

@@ -8,7 +8,7 @@
   <artifactId>activiti-root</artifactId>
 
   <packaging>pom</packaging>
-  <version>5.9-SNAPSHOT</version>
+  <version>5.10-SNAPSHOT</version>
   <properties>
     <spring.framework.version>3.0.3.RELEASE</spring.framework.version>
     <mule.version>3.1.0</mule.version>