Fix NullPointerException when using PluginDependencies since version

1.6.0

Fixes #76
A regression was introduced with the following change:
exec mojo can run executableDependency instead of executable (7684096)

src/it/projects/project6/pom.xml

@@ -0,0 +1,29 @@
+<project>
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.codehaus.mojo.exec.it</groupId>
+        <artifactId>parent</artifactId>
+        <version>0.1</version>
+    </parent>
+
+    <groupId>org.codehaus.mojo.exec.project5</groupId>
+    <artifactId>project5</artifactId>
+    <packaging>pom</packaging>
+    <version>1.0-SNAPSHOT</version>
+    <name>Exec Plugin Example Project 5 Parent</name>
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>junit</groupId>
+                <artifactId>junit</artifactId>
+                <version>3.8.1</version>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+    <modules>
+        <module>project5exec</module>
+        <module>project5lib</module>
+        <module>project5libB</module>
+    </modules>
+</project>

src/it/projects/project6/project5exec/pom.xml

@@ -0,0 +1,71 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <parent>
+        <groupId>org.codehaus.mojo.exec.project5</groupId>
+        <artifactId>project5</artifactId>
+        <version>1.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>project5exec</artifactId>
+    <packaging>jar</packaging>
+    <name>Exec Plugin Example Project 5 Exec</name>
+    <url>http://maven.apache.org</url>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>exec-maven-plugin</artifactId>
+        		<version>@pom.version@</version>
+		        <executions>
+		            <execution>
+		                <phase>process-classes</phase>
+		                <goals>
+		                    <goal>java</goal>
+		                </goals>
+		            </execution>
+		        </executions>
+                <configuration>
+                    <systemProperties>
+                        <systemProperty>
+                            <key>propkey</key>
+                            <value>propvalue</value>
+                        </systemProperty>
+                    </systemProperties>
+                    <mainClass>
+						org.codehaus.mojo.exec.project5libB.App
+					</mainClass>
+                    <arguments>
+                        <argument>argument1</argument>
+                        <argument>argument2</argument>
+                    </arguments>
+                    <includeProjectDependencies>false</includeProjectDependencies>
+                    <includePluginDependencies>true</includePluginDependencies>
+                    <executableDependency>
+                        <groupId>org.codehaus.mojo.exec.project5</groupId>
+                        <artifactId>project5libB</artifactId>
+                    </executableDependency>
+                </configuration>
+                <dependencies>
+                    <dependency>
+                        <groupId>org.codehaus.mojo.exec.project5</groupId>
+                        <artifactId>project5libB</artifactId>
+                        <version>${project.version}</version>
+                    </dependency>
+                    <!--junit dependency is an intentional extraneous dependency-->
+                    <dependency>
+                        <groupId>junit</groupId>
+                        <artifactId>junit</artifactId>
+                        <version>3.8.1</version>
+                        <scope>runtime</scope>
+                    </dependency>
+                </dependencies>
+            </plugin>
+        </plugins>
+    </build>
+    <dependencies>
+        <dependency>
+            <groupId>commons-logging</groupId>
+            <artifactId>commons-logging</artifactId>
+            <version>1.0.4</version>
+        </dependency>
+    </dependencies>
+</project>

src/it/projects/project6/project5lib/pom.xml

@@ -0,0 +1,22 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+	  <parent>
+        <groupId>org.codehaus.mojo.exec.project5</groupId>
+        <artifactId>project5</artifactId>
+        <version>1.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+	<artifactId>project5lib</artifactId>
+	<packaging>jar</packaging>
+	<name>Exec Plugin Example Project 5 Lib</name>
+	<url>http://maven.apache.org</url>
+	<dependencies>
+		<dependency>
+			<groupId>commons-io</groupId>
+			<artifactId>commons-io</artifactId>
+			<version>1.1</version>
+			<scope>runtime</scope>
+		</dependency>
+	</dependencies>
+</project>

src/it/projects/project6/project5lib/src/main/java/org/codehaus/mojo/exec/project5lib/ExampleLibrary.java

@@ -0,0 +1,14 @@
+package org.codehaus.mojo.exec.project5lib;
+
+/**
+ * Used for manual integrationtest of the java goal.
+ *
+ */
+public class ExampleLibrary
+{
+    public ExampleLibrary() {
+    }
+    public boolean isAGoodDay() {
+	    return true;
+    }
+}

src/it/projects/project6/project5libB/pom.xml

@@ -0,0 +1,21 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+	  <parent>
+        <groupId>org.codehaus.mojo.exec.project5</groupId>
+        <artifactId>project5</artifactId>
+        <version>1.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+	<artifactId>project5libB</artifactId>
+	<packaging>jar</packaging>
+	<name>Exec Plugin Example Project 5 Lib B</name>
+	<url>http://maven.apache.org</url>
+	<dependencies>
+		<dependency>
+			<groupId>org.codehaus.mojo.exec.project5</groupId>
+			<artifactId>project5lib</artifactId>
+			<version>${project.version}</version>
+		</dependency>
+	</dependencies>
+</project>

src/it/projects/project6/project5libB/src/main/java/org/codehaus/mojo/exec/project5libB/App.java

@@ -0,0 +1,49 @@
+package org.codehaus.mojo.exec.project5libB;
+
+/**
+ * Used for manual integrationtest of the java goal.
+ *
+ */
+public class App 
+{
+    public static void main( String[] args )
+    {
+        System.out.println("I was started. So obviously I found the main class");
+
+        App app = new App();
+
+    try
+        {
+            Class fileUtils = app.getClass().getClassLoader().loadClass( "org.codehaus.mojo.exec.project5lib.ExampleLibrary" );
+            if ( null != fileUtils )
+            {
+                System.out.println( "Found the ExampleLibrary" );
+            }
+        }
+
+        catch ( Exception e )
+        {
+            System.out.println( "Did not find the ExampleLibrary" );
+        }
+
+        try
+        {
+            Class fileUtils = app.getClass().getClassLoader().loadClass( "org.apache.commons.io.FileUtils" );
+            if ( null != fileUtils )
+            {
+                System.out.println( "Found the runtime dependency" );
+            }
+        }
+        catch ( Exception e )
+        {
+            System.out.println( "Did not find the runtime dependency" );
+        }
+
+
+        String value = System.getProperty("propkey");        
+        if (null != value)
+        {
+            System.out.println("Found the system property passed");
+        }
+    }
+}

src/it/projects/project6/verify.groovy

@@ -0,0 +1,24 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+File log = new File(basedir, 'build.log')
+assert log.exists()
+assert log.getText().contains("I was started. So obviously I found the main class")
+assert log.getText().contains("Found the ExampleLibrary")
+assert log.getText().contains("Found the runtime dependency")
+assert log.getText().contains("Found the system property passed")

src/main/java/org/codehaus/mojo/exec/AbstractExecMojo.java

@@ -249,6 +249,11 @@ protected final MavenSession getSession()
         return session;
     }
 
+    protected final List<Artifact> getPluginDependencies()
+    {
+        return pluginDependencies;
+    }
+
     /**
      * Examine the plugin dependencies to find the executable artifact.
      * 

src/main/java/org/codehaus/mojo/exec/ExecJavaMojo.java

@@ -30,6 +30,8 @@
 import org.apache.maven.project.MavenProject;
 import org.apache.maven.project.ProjectBuilder;
 import org.apache.maven.project.ProjectBuildingRequest;
+import org.apache.maven.shared.artifact.filter.resolve.AndFilter;
+import org.apache.maven.shared.artifact.filter.resolve.TransformableFilter;
 import org.apache.maven.shared.transfer.artifact.resolve.ArtifactResult;
 import org.apache.maven.shared.transfer.dependencies.resolve.DependencyResolver;
 
@@ -53,12 +55,6 @@ public class ExecJavaMojo
     @Component
     private ProjectBuilder projectBuilder;
 
-    /**
-     * @since 1.1-beta-1
-     */
-    @Parameter( readonly = true, defaultValue = "${plugin.artifacts}" )
-    private List<Artifact> pluginDependencies;
-
     /**
      * The main class to execute.<br>
      * With Java 9 and above you can prefix it with the modulename, e.g. <code>com.greetings/com.greetings.Main</code>
@@ -679,7 +675,7 @@ private Set<Artifact> determineRelevantPluginDependencies()
             if ( this.executableDependency == null )
             {
                 getLog().debug( "All Plugin Dependencies will be included." );
-                relevantDependencies = new HashSet<Artifact>( this.pluginDependencies );
+                relevantDependencies = new HashSet<Artifact>( this.getPluginDependencies() );
             }
             else
             {
@@ -715,7 +711,9 @@ private Set<Artifact> resolveExecutableDependencies( Artifact executablePomArtif
             MavenProject executableProject =
                 this.projectBuilder.build( executablePomArtifact, buildingRequest ).getProject();
 
-            for ( ArtifactResult artifactResult : dependencyResolver.resolveDependencies( buildingRequest, executableProject.getModel(), null ) )
+            for ( ArtifactResult artifactResult : dependencyResolver.resolveDependencies( buildingRequest,
+                                                                                          executableProject.getModel(),
+                                                                                          new AndFilter( Collections.<TransformableFilter>emptyList() ) ) )
             {
                 executableDependencies.add( artifactResult.getArtifact() );
             }