use nio for decoding of names - merge from commons-compress rev 746933

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@746934 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/zip/ZipEncodingHelper.java

@@ -168,4 +168,18 @@ abstract class ZipEncodingHelper {
 
         return enc.canEncode(name);
     }
+
+    /**
+     * Decode a filename or a comment from a byte array.
+     * 
+     * @param name The filename or comment.
+     * @param encoding A valid encoding name. The standard zip
+     *                 encoding is <code>"CP437"</code>,
+     *                 <code>"UTF-8"</code> is supported in ZIP file
+     *                 version <code>6.3</code> or later.
+     */
+    static final String decodeName(byte[] name, String encoding) {
+        Charset cs = Charset.forName(encoding);
+        return cs.decode(ByteBuffer.wrap(name)).toString();
+    }
 }

src/main/org/apache/tools/zip/ZipFile.java

@@ -551,9 +551,15 @@ public class ZipFile {
             return new String(bytes);
         } else {
             try {
-                return new String(bytes, enc);
-            } catch (UnsupportedEncodingException uee) {
-                throw new ZipException(uee.getMessage());
+                return ZipEncodingHelper.decodeName(bytes, encoding);
+            } catch (java.nio.charset.UnsupportedCharsetException ex) {
+                // Java 1.4's NIO doesn't recognize a few names that
+                // String.getBytes does
+                try {
+                    return new String(bytes, enc);
+                } catch (UnsupportedEncodingException uee) {
+                    throw new ZipException(uee.getMessage());
+                }
             }
         }
     }