diff --git a/build.xml b/build.xml
index 826366526..18f897505 100644
--- a/build.xml
+++ b/build.xml
@@ -842,6 +842,7 @@
 
 
     <junit printsummary="no" haltonfailure="yes" 
+           filtertrace="off"
            fork="${junit.fork}">
 <!--      <jvmarg value="-classic"/> -->
       <classpath refid="tests-classpath"/>
@@ -922,7 +923,8 @@
 
   <target name="run-single-test" if="testcase" depends="compile-tests">
 
-    <junit printsummary="no" haltonfailure="yes" fork="${junit.fork}">
+    <junit printsummary="no" haltonfailure="yes" fork="${junit.fork}"
+           filtertrace="off">
 <!--      <jvmarg value="-classic"/> -->
       <sysproperty key="build.tests" value="${build.tests}"/>
       <classpath location="${java.home}/lib/classes.zip" />
diff --git a/src/etc/testcases/taskdefs/manifest.xml b/src/etc/testcases/taskdefs/manifest.xml
index 148f05804..a4e320178 100644
--- a/src/etc/testcases/taskdefs/manifest.xml
+++ b/src/etc/testcases/taskdefs/manifest.xml
@@ -100,9 +100,25 @@
     </jar>
   </target>
 
+  <target name="testNoFile">
+    <manifest />
+  </target>
+
+  <target name="testReplace">
+    <copy file="manifests/test2.mf" toFile="mftest.mf" />
+    <manifest file="mftest.mf" />
+  </target>
+
+  <target name="testUpdate">
+    <copy file="manifests/test2.mf" toFile="mftest.mf" />
+    <manifest file="mftest.mf" mode="update">
+      <attribute name="Foo" value="Bar" />
+    </manifest>
+  </target>
+
   <target name="clean">
     <delete>
-      <fileset dir="." includes="mftest*.jar"/>
+      <fileset dir="." includes="mftest*"/>
     </delete>
   </target>
 </project>
diff --git a/src/main/org/apache/tools/ant/taskdefs/Manifest.java b/src/main/org/apache/tools/ant/taskdefs/Manifest.java
index 6864b4195..4ff51bb01 100644
--- a/src/main/org/apache/tools/ant/taskdefs/Manifest.java
+++ b/src/main/org/apache/tools/ant/taskdefs/Manifest.java
@@ -544,6 +544,7 @@ public class Manifest extends Task {
     public Manifest() {
         mode = new Mode();
         mode.setValue("replace");
+        manifestVersion = null;
     }
 
     /**
@@ -613,7 +614,9 @@ public class Manifest extends Task {
      *         to the Manifest spec.
      */
     public void merge(Manifest other) throws ManifestException {
-        manifestVersion = other.manifestVersion;
+        if (other.manifestVersion != null) {
+            manifestVersion = other.manifestVersion;
+        }
         mainSection.merge(other.mainSection);
         for (Enumeration e = other.sections.keys(); e.hasMoreElements();) {
             String sectionName = (String)e.nextElement();
diff --git a/src/testcases/org/apache/tools/ant/taskdefs/ManifestTest.java b/src/testcases/org/apache/tools/ant/taskdefs/ManifestTest.java
index 1eadbbe92..49937a466 100644
--- a/src/testcases/org/apache/tools/ant/taskdefs/ManifestTest.java
+++ b/src/testcases/org/apache/tools/ant/taskdefs/ManifestTest.java
@@ -55,6 +55,8 @@
 package org.apache.tools.ant.taskdefs;
 
 import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
 import java.util.Date;
 import org.apache.tools.ant.BuildFileTest;
 
@@ -192,5 +194,46 @@ public class ManifestTest extends BuildFileTest {
         executeTarget("test14");
     }
      
+    /**
+     * file attribute for manifest task is required.
+     */
+    public void testNoFile() {
+        expectBuildException("testNoFile", "file is required");
+    }
     
+    /**
+     * replace changes Manifest-Version from 2.0 to 1.0
+     */
+    public void testReplace() throws IOException, ManifestException {
+        executeTarget("testReplace");
+        Manifest mf = getManifest();
+        assertNotNull(mf);
+        assertEquals(Manifest.getDefaultManifest(), mf);
+    }
+
+    /**
+     * update keeps the Manifest-Version and adds a new attribute Foo
+     */
+    public void testUpdate() throws IOException, ManifestException {
+        executeTarget("testUpdate");
+        Manifest mf = getManifest();
+        assertNotNull(mf);
+        assertTrue(!Manifest.getDefaultManifest().equals(mf));
+        String mfAsString = mf.toString();
+        assertNotNull(mfAsString);
+        assertTrue(mfAsString.startsWith("Manifest-Version: 2.0"));
+        assertTrue(mfAsString.indexOf("Foo: Bar") > -1);
+    }
+
+    /**
+     * Reads mftest.mf.
+     */
+    private Manifest getManifest() throws IOException, ManifestException {
+        FileReader r = new FileReader("src/etc/testcases/taskdefs/mftest.mf");
+        try {
+            return new Manifest(r);
+        } finally {
+            r.close();
+        }
+    }
 }