[MNG-5868] No duplicate artifacts in attached artifacts

if attached artifacts already contains the artifact remove it and add the new one

Signed-off-by: olivier lamy <olamy@apache.org>

maven-core/src/main/java/org/apache/maven/project/MavenProject.java

@@ -72,6 +72,8 @@ import org.codehaus.plexus.classworlds.realm.ClassRealm;
 import org.codehaus.plexus.util.xml.Xpp3Dom;
 import org.eclipse.aether.graph.DependencyFilter;
 import org.eclipse.aether.repository.RemoteRepository;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * The concern of the project is provide runtime values based on the model.
@@ -90,6 +92,9 @@ import org.eclipse.aether.repository.RemoteRepository;
 public class MavenProject
     implements Cloneable
 {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger( MavenProject.class );
+
     public static final String EMPTY_PROJECT_GROUP_ID = "unknown";
 
     public static final String EMPTY_PROJECT_ARTIFACT_ID = "empty-project";
@@ -122,7 +127,7 @@ public class MavenProject
 
     private List<RemoteRepository> remotePluginRepositories;
 
-    private List<Artifact> attachedArtifacts;
+    private List<Artifact> attachedArtifacts = new ArrayList<>();
 
     private MavenProject executionProject;
 
@@ -921,12 +926,23 @@ public class MavenProject
      * coordinates.
      *
      * @param artifact the artifact to add or replace.
-     * @throws DuplicateArtifactAttachmentException
+     * @deprecated Please use {@link MavenProjectHelper}
+     * @throws DuplicateArtifactAttachmentException will never happen but leave it for backward compatibility
      */
     public void addAttachedArtifact( Artifact artifact )
         throws DuplicateArtifactAttachmentException
     {
-        getAttachedArtifacts().add( artifact );
+        // if already there we remove it and add again
+        int index = attachedArtifacts.indexOf( artifact );
+        if ( index >= 0 )
+        {
+            LOGGER.warn( "artifact {} already attached, replace previous instance", artifact );
+            attachedArtifacts.set( index, artifact );
+        }
+        else
+        {
+            attachedArtifacts.add( artifact );
+        }
     }
 
     public List<Artifact> getAttachedArtifacts()
@@ -935,7 +951,7 @@ public class MavenProject
         {
             attachedArtifacts = new ArrayList<>();
         }
-        return attachedArtifacts;
+        return Collections.unmodifiableList( attachedArtifacts );
     }
 
     public Xpp3Dom getGoalConfiguration( String pluginGroupId, String pluginArtifactId, String executionId,

maven-core/src/test/java/org/apache/maven/DefaultMavenTest.java

@@ -1,7 +1,14 @@
 package org.apache.maven;
 
+import org.apache.maven.artifact.Artifact;
+import org.apache.maven.artifact.DefaultArtifact;
 import org.apache.maven.execution.MavenExecutionRequest;
 import org.apache.maven.execution.MavenExecutionResult;
+import org.apache.maven.project.MavenProject;
+import org.apache.maven.project.MavenProjectHelper;
+
+import java.io.File;
+import java.nio.file.Files;
 
 import static java.util.Arrays.asList;
 
@@ -23,7 +30,9 @@ import static java.util.Arrays.asList;
  * specific language governing permissions and limitations
  * under the License.
  */
-public class DefaultMavenTest extends AbstractCoreMavenComponentTestCase{
+public class DefaultMavenTest
+    extends AbstractCoreMavenComponentTestCase
+{
 
     public void testThatErrorDuringProjectDependencyGraphCreationAreStored()
             throws Exception
@@ -42,4 +51,24 @@ public class DefaultMavenTest extends AbstractCoreMavenComponentTestCase{
         return "src/test/projects/default-maven";
     }
 
+
+    public void testMavenProjectNoDuplicateArtifacts()
+        throws Exception
+    {
+        MavenProjectHelper mavenProjectHelper = lookup( MavenProjectHelper.class );
+        MavenProject mavenProject = new MavenProject();
+        mavenProject.setArtifact( new DefaultArtifact( "g", "a", "1.0", Artifact.SCOPE_TEST, "jar", "", null ) );
+        File artifactFile = Files.createTempFile( "foo", "tmp").toFile();
+        try
+        {
+            mavenProjectHelper.attachArtifact( mavenProject, "sources", artifactFile );
+            assertEquals( 1, mavenProject.getAttachedArtifacts().size() );
+            mavenProjectHelper.attachArtifact( mavenProject, "sources", artifactFile );
+            assertEquals( 1, mavenProject.getAttachedArtifacts().size() );
+        } finally
+        {
+            Files.deleteIfExists( artifactFile.toPath() );
+        }
+    }
+
 }