Bugzilla 45098: update jar index with no other changes

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@690714 13f79535-47bb-0310-9956-ffa450edef68

WHATSNEW

@@ -316,6 +316,10 @@ Other changes:
    manual page for details.
    Bugzilla Report 37241.
 
+ * The Jar task now supports the addition of a jar index file in update mode.
+   Previously the absence of the index was not enough to trigger the rebuild;
+   some other update was necessary.  Bugzilla report 45098.
+
 Changes from Ant 1.7.0 TO Ant 1.7.1
 =============================================
 

src/main/org/apache/tools/ant/taskdefs/Jar.java

@@ -340,6 +340,29 @@ public class Jar extends Zip {
         return newManifest;
     }
 
+    private boolean jarHasIndex(File jarFile) throws IOException {
+        ZipFile zf = null;
+        try {
+            zf = new ZipFile(jarFile);
+            Enumeration e = zf.entries();
+            while (e.hasMoreElements()) {
+                ZipEntry ze = (ZipEntry) e.nextElement();
+                if (ze.getName().equalsIgnoreCase(INDEX_NAME)) {
+                    return true;
+                }
+            }
+            return false;
+        } finally {
+            if (zf != null) {
+                try {
+                    zf.close();
+                } catch (IOException e) {
+                    // XXX - log an error?  throw an exception?
+                }
+            }
+        }
+    }
+    
     /**
      * Behavior when a Manifest is found in a zipfileset or zipgroupfileset file.
      * Valid values are "skip", "merge", and "mergewithoutmain".
@@ -593,7 +616,7 @@ public class Jar extends Zip {
             }
         } else if (INDEX_NAME.equalsIgnoreCase(vPath) && index) {
             log("Warning: selected " + archiveType
-                + " files include a META-INF/INDEX.LIST which will"
+                + " files include a " + INDEX_NAME + " which will"
                 + " be replaced by a newly generated one.", Project.MSG_WARN);
         } else {
             if (index && vPath.indexOf("/") == -1) {
@@ -734,6 +757,14 @@ public class Jar extends Zip {
         }
 
         createEmpty = needsUpdate;
+        if (!needsUpdate && index) {
+            try {
+                needsUpdate = !jarHasIndex(zipFile);
+            } catch (IOException e) {
+                //if we couldn't read it, we might as well recreate it?
+                needsUpdate = true;
+            }
+        }
         return super.getResourcesToAdd(rcs, zipFile, needsUpdate);
     }
 

src/tests/antunit/taskdefs/jar-test.xml

@@ -0,0 +1,52 @@
+<?xml version="1.0"?>
+<!--
+  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.
+-->
+<project default="antunit" xmlns:au="antlib:org.apache.ant.antunit">
+  <import file="../antunit-base.xml" />
+
+  <property name="index.jar" location="index.jar" />
+
+  <target name="tearDown">
+    <delete file="${index.jar}" />
+  </target>
+
+  <target name="testIndexOnlyUpdate">
+    <jar destfile="${index.jar}" index="false">
+      <fileset dir="${basedir}" includes="*-test.xml" />
+    </jar>
+    <au:assertTrue>
+      <resourcecount count="0">
+        <restrict>
+          <zipentry zipfile="${index.jar}" name="META-INF/INDEX.LIST" />
+          <exists />
+        </restrict>
+      </resourcecount>
+    </au:assertTrue>
+    <jar destfile="${index.jar}" index="true" update="true">
+      <fileset dir="${basedir}" includes="*-test.xml" />
+    </jar>
+    <au:assertTrue>
+      <resourcecount count="1">
+        <restrict>
+          <zipentry zipfile="${index.jar}" name="META-INF/INDEX.LIST" />
+          <exists />
+        </restrict>
+      </resourcecount>
+    </au:assertTrue>
+  </target>
+
+</project>