compute effective properties permitting null values

src/main/org/apache/tools/ant/util/ScriptRunnerBase.java

@@ -27,8 +27,6 @@ import java.nio.charset.Charset;
 import java.nio.file.Files;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.function.Function;
-import java.util.stream.Collectors;
 
 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.Project;
@@ -335,8 +333,9 @@ public abstract class ScriptRunnerBase {
     public void bindToComponent(ProjectComponent component) {
         project = component.getProject();
 
-        addBeans(project.getPropertyNames().stream()
-            .collect(Collectors.toMap(Function.identity(), project::getProperty)));
+        final Map<String, Object> effectiveProperties = new HashMap<>();
+        project.getPropertyNames().forEach(n -> effectiveProperties.put(n, project.getProperty(n)));
+        addBeans(effectiveProperties);
         addBeans(project.getCopyOfTargets());
         addBeans(project.getCopyOfReferences());
         addBean("project", project);