From 0bfec136dbcc219aa8fef9d0501998eefa705ff5 Mon Sep 17 00:00:00 2001
From: Benjamin Bentmann <bentmann@apache.org>
Date: Thu, 18 Nov 2010 19:28:53 +0000
Subject: [PATCH] [MNG-4904] Make
 MavenExecutionResult.getTopologicallySortedProjects() return empty list
 instead of null Submitted by: Basil James Whitehouse III

git-svn-id: https://svn.apache.org/repos/asf/maven/maven-3/trunk@1036585 13f79535-47bb-0310-9956-ffa450edef68
---
 .../execution/DefaultMavenExecutionResult.java      |  2 +-
 .../maven/execution/MavenExecutionResult.java       |  4 ++++
 .../maven/execution/DefaultMavenExecutionTest.java  | 13 +++++++++++++
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/maven-core/src/main/java/org/apache/maven/execution/DefaultMavenExecutionResult.java b/maven-core/src/main/java/org/apache/maven/execution/DefaultMavenExecutionResult.java
index bdb4532a54..c00628319c 100644
--- a/maven-core/src/main/java/org/apache/maven/execution/DefaultMavenExecutionResult.java
+++ b/maven-core/src/main/java/org/apache/maven/execution/DefaultMavenExecutionResult.java
@@ -63,7 +63,7 @@ public class DefaultMavenExecutionResult
 
     public List<MavenProject> getTopologicallySortedProjects()
     {
-        return topologicallySortedProjects;
+        return null == topologicallySortedProjects ? Collections.<MavenProject> emptyList() : topologicallySortedProjects;
     }
 
     public DependencyResolutionResult getDependencyResolutionResult()
diff --git a/maven-core/src/main/java/org/apache/maven/execution/MavenExecutionResult.java b/maven-core/src/main/java/org/apache/maven/execution/MavenExecutionResult.java
index 15ce3e75d1..dd0466567a 100644
--- a/maven-core/src/main/java/org/apache/maven/execution/MavenExecutionResult.java
+++ b/maven-core/src/main/java/org/apache/maven/execution/MavenExecutionResult.java
@@ -33,6 +33,10 @@ public interface MavenExecutionResult
     MavenProject getProject();
 
     MavenExecutionResult setTopologicallySortedProjects( List<MavenProject> projects );
+    
+    /**
+     * @return the sorted list, or an empty list if there are no projects.
+     */
     List<MavenProject> getTopologicallySortedProjects();
 
     MavenExecutionResult setDependencyResolutionResult( DependencyResolutionResult result );
diff --git a/maven-core/src/test/java/org/apache/maven/execution/DefaultMavenExecutionTest.java b/maven-core/src/test/java/org/apache/maven/execution/DefaultMavenExecutionTest.java
index 99d55eafba..698c6d1514 100644
--- a/maven-core/src/test/java/org/apache/maven/execution/DefaultMavenExecutionTest.java
+++ b/maven-core/src/test/java/org/apache/maven/execution/DefaultMavenExecutionTest.java
@@ -19,6 +19,10 @@ package org.apache.maven.execution;
  * under the License.
  */
 
+import org.apache.maven.project.MavenProject;
+
+import java.util.List;
+
 import junit.framework.TestCase;
 
 /**
@@ -35,5 +39,14 @@ public class DefaultMavenExecutionTest
         assertNotNull( copy );
         assertNotSame( copy, original );
     }
+    
+    public void testResultWithNullTopologicallySortedProjectsIsEmptyList()
+    {
+        MavenExecutionResult result = new DefaultMavenExecutionResult();
+        result.setTopologicallySortedProjects( null );
+        List<MavenProject> projects = result.getTopologicallySortedProjects();
+        assertNotNull( projects );
+        assertTrue( projects.isEmpty() );
+    }
 
 }