* Added new task <ant-call> to core, which can execute a named target

in the current project, or any referenced project.
* <ant1.ant> now works by executing AntTask.
* Fixed minor bug in DefaultClassloaderManager which was causing NPEs
  in URLClassLoader.
* DefaultTaskContext now removes properties when they are set to null.
  (rather than throwing a NPE inside HashMap).


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@272067 13f79535-47bb-0310-9956-ffa450edef68

proposal/myrmidon/ant1compat.xml

@@ -63,6 +63,8 @@
           <exclude name="${ant1.package}/ant/Main.class"/>
           <exclude name="${ant1.package}/ant/Task.class"/>
           <exclude name="${ant1.package}/ant/BuildException.class"/>
+          <exclude name="${ant1.package}/ant/taskdefs/Ant.class"/>
+          <exclude name="${ant1.package}/ant/taskdefs/CallTarget.class"/>
           <exclude name="${ant1.package}/ant/types/Path.class"/>
         </patternset>
 

proposal/myrmidon/src/ant1compat/ant-descriptor.xml

@@ -12,13 +12,15 @@
         <!-- TaskAdapter tasks -->
         <task name="ant1.condition"
             classname="org.apache.tools.ant.Ant1CompatTaskAdapter" />
+            
+        <!-- Tasks specialised for myrmidon -->
+        <task name="ant1.ant"
+              classname="org.apache.tools.ant.taskdefs.Ant" />
 
         <!-- Tasks not currently supported.
 
                 <task name="ant1.antcall"
                     classname="org.apache.tools.ant.taskdefs.CallTarget" />
-                <task name="ant1.ant"
-                    classname="org.apache.tools.ant.taskdefs.Ant" />
         -->
 
         <!-- standard ant tasks -->

proposal/myrmidon/src/ant1compat/org/apache/tools/ant/taskdefs/Ant.java

@@ -0,0 +1,300 @@
+/*
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2000-2002 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ *    any, must include the following acknowlegement:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowlegement may appear in the software itself,
+ *    if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Ant", and "Apache Software
+ *    Foundation" must not be used to endorse or promote products derived
+ *    from this software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ *    nor may "Apache" appear in their names without prior written
+ *    permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+
+package org.apache.tools.ant.taskdefs;
+
+import org.apache.tools.ant.Task;
+import org.apache.tools.ant.BuildException;
+import org.apache.tools.ant.util.FileUtils;
+import org.apache.avalon.framework.configuration.DefaultConfiguration;
+import org.apache.avalon.framework.configuration.Configuration;
+import org.apache.myrmidon.interfaces.executor.Executor;
+import org.apache.myrmidon.interfaces.executor.ExecutionFrame;
+import org.apache.myrmidon.api.TaskException;
+import java.io.File;
+import java.util.Vector;
+import java.util.Iterator;
+
+/**
+ * Call Ant in a sub-project.
+ *
+ *  <pre>
+ *  &lt;target name=&quot;foo&quot; depends=&quot;init&quot;&gt;
+ *    &lt;ant antfile=&quot;build.xml&quot; target=&quot;bar&quot; &gt;
+ *      &lt;property name=&quot;property1&quot; value=&quot;aaaaa&quot; /&gt;
+ *      &lt;property name=&quot;foo&quot; value=&quot;baz&quot; /&gt;
+ *    &lt;/ant&gt;</SPAN>
+ *  &lt;/target&gt;</SPAN>
+ *
+ *  &lt;target name=&quot;bar&quot; depends=&quot;init&quot;&gt;
+ *    &lt;echo message=&quot;prop is ${property1} ${foo}&quot; /&gt;
+ *  &lt;/target&gt;
+ * </pre>
+ *
+ *
+ * @author costin@dnt.ro
+ * @author <a href="mailto:darrell@apache.org">Darrell DeBoer</a>
+ */
+public class Ant extends Task {
+
+    /** the basedir where is executed the build file */
+    private File dir = null;
+    
+    /** the build.xml file (can be absolute) in this case dir will be ignored */
+    private String antFile = null;
+    
+    /** the target to call if any */
+    private String target = null;
+    
+    /** the output */
+    private String output = null;
+    
+    /** should we inherit properties from the parent ? */
+    private boolean inheritAll = true;
+    
+    /** should we inherit references from the parent ? */
+    private boolean inheritRefs = false;
+    
+    /** the properties to pass to the new project */
+    private Vector properties = new Vector();
+    
+    /** the references to pass to the new project */
+    private Vector references = new Vector();
+
+    /**
+     * If true, inherit all properties from parent Project
+     * If false, inherit only userProperties and those defined
+     * inside the ant call itself
+     */
+    public void setInheritAll(boolean value) {
+       inheritAll = value;
+    }
+
+    /**
+     * If true, inherit all references from parent Project
+     * If false, inherit only those defined
+     * inside the ant call itself
+     */
+    public void setInheritRefs(boolean value) {
+        inheritRefs = value;
+    }
+
+    /**
+     * ...
+     */
+    public void setDir(File d) {
+        this.dir = d;
+    }
+
+    /**
+     * set the build file, it can be either absolute or relative.
+     * If it is absolute, <tt>dir</tt> will be ignored, if it is
+     * relative it will be resolved relative to <tt>dir</tt>.
+     */
+    public void setAntfile(String s) {
+        // @note: it is a string and not a file to handle relative/absolute
+        // otherwise a relative file will be resolved based on the current
+        // basedir.
+        this.antFile = s;
+    }
+
+    /**
+     * set the target to execute. If none is defined it will
+     * execute the default target of the build file
+     */
+    public void setTarget(String s) {
+        this.target = s;
+    }
+
+    public void setOutput(String s) {
+        this.output = s;
+    }
+
+    /** create a property to pass to the new project as a 'user property' */
+    public Property createProperty() {
+        Property p = new Property(true);
+        properties.addElement( p );
+        return p;
+    }
+
+    /** 
+     * create a reference element that identifies a data type that
+     * should be carried over to the new project.
+     */
+    public void addReference(Reference r) {
+        references.addElement(r);
+    }
+
+    /**
+     * Helper class that implements the nested &lt;reference&gt;
+     * element of &lt;ant&gt; and &lt;antcall&gt;.
+     */
+    public static class Reference 
+        extends org.apache.tools.ant.types.Reference {
+
+        public Reference() {super();}
+        
+        private String targetid=null;
+        public void setToRefid(String targetid) { this.targetid=targetid; }
+        public String getToRefid() { return targetid; }
+    }
+
+    /**
+     * Called by the project to let the task do its work. This method may be
+     * called more than once, if the task is invoked more than once.
+     * For example,
+     * if target1 and target2 both depend on target3, then running
+     * "ant target1 target2" will run all tasks in target3 twice.
+     *
+     * @exception BuildException if something goes wrong with the build
+     */
+    public void execute() throws BuildException
+    {
+        Object ant1project = unsetProject();
+
+        try
+        {
+            Configuration antConfig = buildAntTaskConfiguration();
+
+            executeTask( antConfig );
+        }
+        finally
+        {
+            resetProject( ant1project );
+        }
+    }
+
+    private void executeTask( Configuration antConfig )
+    {
+        try
+        {
+            Executor executor = (Executor) m_context.getService( Executor.class );
+            ExecutionFrame frame =
+                (ExecutionFrame) m_context.getService( ExecutionFrame.class );
+            executor.execute( antConfig, frame );
+        }
+        catch( TaskException e )
+        {
+            throw new BuildException( e );
+        }
+    }
+
+    private Configuration buildAntTaskConfiguration()
+    {
+        DefaultConfiguration antConfig = new DefaultConfiguration( "ant", "" );
+
+        antConfig.setAttribute( "inherit-all", String.valueOf( inheritAll ) );
+
+        // Ignore inheritRefs for now ( inheritAll == inheritRefs )
+
+        if ( target != null )
+        {
+            antConfig.setAttribute( "target", target );
+        }
+
+        // Get the "file" value.
+        if (antFile == null) {
+            antFile = "build.xml";
+        }
+
+        if ( dir == null )
+        {
+            dir = project.getBaseDir();
+        }
+
+        File file = FileUtils.newFileUtils().resolveFile(dir, antFile);
+        antFile = file.getAbsolutePath();
+
+        antConfig.setAttribute( "file", antFile );
+
+        // Add all of the properties.
+        Iterator iter = properties.iterator();
+        while( iter.hasNext() )
+        {
+            DefaultConfiguration param = new DefaultConfiguration( "param", "" );
+            Property property = (Property)iter.next();
+            param.setAttribute( "name", property.getName() );
+            param.setAttribute( "value", property.getValue() );
+            antConfig.addChild( param );
+        }
+        return antConfig;
+    }
+
+    private void resetProject( Object ant1project ) throws BuildException
+    {
+        try
+        {
+            m_context.setProperty( "ant1.project", ant1project );
+        }
+        catch( TaskException e )
+        {
+            throw new BuildException( e );
+        }
+    }
+
+    private Object unsetProject() throws BuildException
+    {
+        Object ant1project = null;
+        try
+        {
+            ant1project = m_context.getProperty( "ant1.project" );
+            m_context.setProperty( "ant1.project", null );
+        }
+        catch( TaskException e )
+        {
+            throw new BuildException( e );
+        }
+        return ant1project;
+    }
+}

proposal/myrmidon/src/java/org/apache/antlib/core/AbstractAntTask.java

@@ -0,0 +1,179 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included  with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.antlib.core;
+
+import org.apache.myrmidon.api.AbstractTask;
+import org.apache.myrmidon.api.TaskException;
+import org.apache.myrmidon.interfaces.model.Project;
+import org.apache.myrmidon.interfaces.workspace.Workspace;
+import org.apache.myrmidon.interfaces.embeddor.Embeddor;
+import org.apache.avalon.framework.parameters.Parameters;
+import java.util.Map;
+import java.util.Iterator;
+import java.util.ArrayList;
+
+/**
+ * Abstract base class for Tasks which execute targets.
+ *
+ * @author <a href="mailto:peter@apache.org">Peter Donald</a>
+ * @author <a href="mailto:darrell@apache.org">Darrell DeBoer</a>
+ * @version $Revision$ $Date$
+ */
+public abstract class AbstractAntTask extends AbstractTask
+{
+    /**
+     * If true, inherit all properties from parent Project
+     * If false, inherit only userProperties and those defined
+     * inside the ant call itself
+     */
+    private boolean m_inheritAll;
+    /**
+     * The target to process in build file. If not specified
+     * will use default in specified build file.
+     */
+    private String m_target;
+    private final ArrayList m_parameters = new ArrayList();
+
+    /**
+     * Specify whether should inherit properties in sub-build.
+     *
+     * @param inheritAll true to inherit else false
+     */
+    public void setInheritAll( final boolean inheritAll )
+    {
+        m_inheritAll = inheritAll;
+    }
+
+    /**
+     * set the target to process. If none is defined it will
+     * execute the default target of the build file
+     */
+    public void setTarget( final String target )
+    {
+        m_target = target;
+    }
+
+    /**
+     * Add a parameter to processing of build file.
+     *
+     * @param param the parameter
+     */
+    public void addParam( final AntParam param )
+    {
+        m_parameters.add( param );
+    }
+
+    /**
+     * Execute the specified build, with specified parameters.
+     *
+     * @throws TaskException if an error occurs.
+     */
+    public void execute()
+        throws TaskException
+    {
+        try
+        {
+            Project project = getProject();
+
+            Embeddor embeddor = getEmbeddor();
+
+            final Workspace workspace =
+                embeddor.createWorkspace( buildParameters() );
+
+            workspace.addProjectListener( embeddor.createListener("default"));
+
+            if( null == m_target )
+            {
+                m_target = project.getDefaultTargetName();
+            }
+
+            workspace.executeProject( project, m_target );
+        }
+        catch( final Exception e )
+        {
+            throw new TaskException( e.toString(), e );
+        }
+    }
+
+    /**
+     * A convenience method for obtaining the Embeddor from the
+     * TaskContext.
+     * @return The Embeddor contained in the TaskContext
+     * @throws TaskException if the Embeddor could not be obtained.
+     */
+    protected Embeddor getEmbeddor() throws TaskException
+    {
+        final Embeddor embeddor =
+            (Embeddor)getContext().getService( Embeddor.class );
+        return embeddor;
+    }
+
+    /**
+     * Get/create/build the project containing the target to be executed.
+     * Subclasses will override this method to provide different means
+     * of obtaining a project to execute.
+     * @return The project containing the target to execute.
+     * @throws Exception If a problem occurred building the project.
+     */
+    protected abstract Project getProject() throws Exception;
+
+    /**
+     * Build the parameters to pass to sub-project.
+     * These include the current tasks properties
+     * (if inheritall=true) and any supplied by the user.
+     *
+     * @return the created parameters
+     */
+    private Parameters buildParameters()
+        throws TaskException
+    {
+        final Parameters parameters = new Parameters();
+
+        if( m_inheritAll )
+        {
+            final Map properties = getContext().getProperties();
+            final Iterator keys = properties.keySet().iterator();
+            while( keys.hasNext() )
+            {
+                final String key = (String)keys.next();
+                final Object value = properties.get( key );
+                setProperty( parameters, key, value );
+            }
+        }
+
+        final int size = m_parameters.size();
+        for( int i = 0; i < size; i++ )
+        {
+            final AntParam param = (AntParam)m_parameters.get( i );
+            param.validate();
+            final String name = param.getName();
+            final String value = param.getValue().toString();
+            setProperty( parameters, name, value );
+        }
+
+        return parameters;
+    }
+
+    /**
+     * Utility method to add the property into parameters object.
+     *
+     * @param parameters where to put property
+     * @param name the property
+     * @param value the value of property
+     * @todo allow non-string params to be passed down
+     */
+    private void setProperty( final Parameters parameters,
+                              final String name,
+                              final Object value )
+    {
+        if( !name.startsWith( "myrmidon." ) )
+        {
+            parameters.setParameter( name, value.toString() );
+        }
+    }
+}

proposal/myrmidon/src/java/org/apache/antlib/core/AntCallTask.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included  with this distribution in
+ * the LICENSE.txt file.
+ */
+package org.apache.antlib.core;
+
+import org.apache.avalon.excalibur.i18n.ResourceManager;
+import org.apache.avalon.excalibur.i18n.Resources;
+import org.apache.myrmidon.api.TaskException;
+import org.apache.myrmidon.interfaces.model.Project;
+
+/**
+ * A task which executes a target in the current project,
+ * or a referenced project.
+ *
+ * @author <a href="mailto:darrell@apache.org">Darrell DeBoer</a>
+ * @version $Revision$ $Date$
+ * @ant.task name="ant-call"
+ */
+public class AntCallTask extends AbstractAntTask
+{
+    private final static Resources REZ =
+        ResourceManager.getPackageResources( AntCallTask.class );
+
+    private String m_project;
+
+    /**
+     * Specifies the project to execute. If not specified, the current
+     * project is used.
+     * @param project the name of the Project to execute.
+     */
+    public void setProject( String project )
+    {
+        m_project = project;
+    }
+
+    /**
+     * Get/create/build the project which will be executed.
+     * Subclasses will override this method to provide different means
+     * of obtaining a project to execute.
+     * @return The project containing the target to execute.
+     * @throws Exception If a problem occurred building the project.
+     */
+    protected Project getProject() throws Exception
+    {
+        Project currentProject =
+            (Project)getContext().getService( Project.class );
+
+        // By default, use the current project.
+        Project referencedProject = currentProject;
+
+        if( m_project != null )
+        {
+            referencedProject = currentProject.getProject( m_project );
+            if( referencedProject == null )
+            {
+                final String message =
+                    REZ.getString( "antcall.invalid-project.error" );
+                throw new TaskException( message );
+            }
+        }
+
+        return referencedProject;
+    }
+}

proposal/myrmidon/src/java/org/apache/antlib/core/AntTask.java

@@ -8,66 +8,35 @@
 package org.apache.antlib.core;
 
 import java.io.File;
-import java.util.ArrayList;
-import java.util.Iterator;
-import java.util.Map;
 import org.apache.avalon.framework.parameters.Parameters;
-import org.apache.myrmidon.api.AbstractTask;
-import org.apache.myrmidon.api.TaskException;
-import org.apache.myrmidon.interfaces.embeddor.Embeddor;
 import org.apache.myrmidon.interfaces.model.Project;
-import org.apache.myrmidon.interfaces.workspace.Workspace;
 
 /**
- * Create a new Workspace and process a build in
- * that new workspace.
+ * Executes a target in a named build file.
  *
  * @author <a href="mailto:peter@apache.org">Peter Donald</a>
  * @ant.task name="ant"
  */
 public class AntTask
-    extends AbstractTask
+
+    extends AbstractAntTask
 {
     /**
      * Default build file.
      */
     private static final String DEFAULT_BUILD_FILE = "build.ant";
 
-    /**
-     * If true, inherit all properties from parent Project
-     * If false, inherit only userProperties and those defined
-     * inside the ant call itself
-     */
-    private boolean m_inheritAll;
-
     /**
      * The build file which to execute. If not set defaults to
      * using "build.ant" in the basedir of current project.
      */
     private File m_file;
 
-    /**
-     * The target to process in build file. If not specified
-     * will use default in specified build file.
-     */
-    private String m_target;
-
     /**
      * The "type" of the build file. By default this is null which
      * means the type will be determined by the build file extension.
      */
     private String m_type;
-    private final ArrayList m_parameters = new ArrayList();
-
-    /**
-     * Specify whether should inherit properties in sub-build.
-     *
-     * @param inheritAll true to inherit else false
-     */
-    public void setInheritAll( final boolean inheritAll )
-    {
-        m_inheritAll = inheritAll;
-    }
 
     /**
      * set the build file to process.
@@ -90,114 +59,21 @@ public class AntTask
     }
 
     /**
-     * set the target to process. If none is defined it will
-     * execute the default target of the build file
+     * @return The project containing the target to execute.
+     * @throws Exception If a problem occurred building the project.
      */
-    public void setTarget( final String target )
-    {
-        m_target = target;
-    }
-
-    /**
-     * Add a parameter to processing of build file.
-     *
-     * @param param the parameter
-     */
-    public void addParam( final AntParam param )
-    {
-        m_parameters.add( param );
-    }
-
-    /**
-     * Execute the specified build, with specified parameters.
-     *
-     * @throws TaskException if an error occurs.
-     */
-    public void execute()
-        throws TaskException
+    protected Project getProject() throws Exception
     {
         if( null == m_file )
         {
             m_file = getContext().resolveFile( DEFAULT_BUILD_FILE );
         }
 
-        final Embeddor embeddor =
-            (Embeddor)getContext().getService( Embeddor.class );
-
-        try
-        {
-            final Project project =
-                embeddor.createProject( m_file.toString(),
-                                        m_type,
-                                        new Parameters() );
-            final Workspace workspace =
-                embeddor.createWorkspace( buildParameters() );
-
-            if( null == m_target )
-            {
-                m_target = project.getDefaultTargetName();
-            }
-
-            workspace.executeProject( project, m_target );
-        }
-        catch( final Exception e )
-        {
-            throw new TaskException( e.toString(), e );
-        }
-    }
-
-    /**
-     * Build the parameters to pass to sub-project.
-     * These include the current tasks properties
-     * (if inheritall=true) and any supplied by the user.
-     *
-     * @return the created parameters
-     */
-    private Parameters buildParameters()
-        throws TaskException
-    {
-        final Parameters parameters = new Parameters();
-
-        if( m_inheritAll )
-        {
-            final Map properties = getContext().getProperties();
-            final Iterator keys = properties.keySet().iterator();
-            while( keys.hasNext() )
-            {
-                final String key = (String)keys.next();
-                final Object value = properties.get( key );
-                setProperty( parameters, key, value );
-            }
-        }
-
-        final int size = m_parameters.size();
-        for( int i = 0; i < size; i++ )
-        {
-            final AntParam param = (AntParam)m_parameters.get( i );
-            param.validate();
-            final String name = param.getName();
-            final String value = param.getValue().toString();
-            setProperty( parameters, name, value );
-        }
-
-        return parameters;
+        final Project project =
+            getEmbeddor().createProject( m_file.toString(),
+                                         m_type,
+                                         new Parameters() );
+        return project;
     }
 
-    /**
-     * Utility method to add the property into parameters object.
-     *
-     * @param parameters where to put property
-     * @param name the property
-     * @param value the value of property
-     * @todo allow non-string params to be passed down
-     */
-    private void setProperty( final Parameters parameters,
-                              final String name,
-                              final Object value )
-    {
-        if( !name.startsWith( "myrmidon." ) )
-        {
-            parameters.setParameter( name, value.toString() );
-        }
-    }
 }

proposal/myrmidon/src/java/org/apache/antlib/core/Resources.properties

@@ -34,4 +34,6 @@ filetokenset.not-a-file.error=File {0} does not exist, or is not a file.
 filetokenset.read-tokens.error=Could not read tokens from {0}.
 
 param.noname.error=Missing name from parameter.
-param.novalue.error=Missing value from parameter "{0}".
+param.novalue.error=Missing value from parameter "{0}".
+
+antcall.invalid-project.error=Project-reference "{0}" not found.

proposal/myrmidon/src/java/org/apache/myrmidon/components/classloader/DefaultClassLoaderManager.java

@@ -155,7 +155,7 @@ public class DefaultClassLoaderManager
     private URL[] buildClasspath( final ArrayList files )
         throws MalformedURLException
     {
-        final URL[] urls = new URL[ files.size() + 1 ];
+        final URL[] urls = new URL[ files.size() ];
         final int count = files.size();
         for( int i = 0; i < count; i++ )
         {

proposal/myrmidon/src/java/org/apache/myrmidon/components/workspace/DefaultTaskContext.java

@@ -214,7 +214,15 @@ public class DefaultTaskContext
     {
         checkPropertyName( name );
         checkPropertyValid( name, value );
-        m_contextData.put( name, value );
+
+        if ( value == null )
+        {
+            m_contextData.remove( name );
+        }
+        else
+        {
+            m_contextData.put( name, value );
+        }
     }
 
     /**

proposal/myrmidon/src/make/sample.ant

@@ -279,6 +279,32 @@ Legal:
         <ant/>
     </target>
 
+    <target name="antcall-test">
+        <log message="Testing antcall task..."/>
+        <ant-call target="if-test"/>
+
+        <log message="Using params..."/>
+        <ant-call target="prop-print">
+            <param name="meep.meep" value="Meep!"/>
+        </ant-call>
+
+        <log message="Using params value-ref..."/>
+        <pattern id="meep.data" name="*.java" if="..." />
+        <ant-call target="prop-print">
+            <param name="meep.meep" value-ref="meep.data"/>
+        </ant-call>
+
+        <log message="Using inheritall..."/>
+        <pattern id="meep.meep" name="*.java" if="..." />
+        <ant-call target="prop-print" inherit-all="true"/>
+
+        <log message="Calling referenced project, default target..."/>
+        <ant-call project="prim"/>
+
+        <log message="Calling referenced project, named target..."/>
+        <ant-call project="prim" target="extensions-test"/>
+    </target>
+
     <target name="prop-print">
         <log message="Give me a property ... ${meep.meep}"/>
     </target>