Fix logic of last patch to make <zipfileset src="foo.zip" /> work again.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@269726 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -428,15 +428,15 @@ public class Zip extends MatchingTask {
                 entry = new ZipEntry(origEntry);
                 String vPath = entry.getName();
                 if (zipScanner.match(vPath)) {
-                    if (prefix.length() > 0) {
+                    if (fullpath.length() > 0) {
+                        addParentDirs(null, fullpath, zOut, "");
+                        zipFile(in, zOut, fullpath, entry.getTime());
+                    } else {
                         addParentDirs(null, vPath, zOut, prefix);
                         if (! entry.isDirectory()) {
                             zipFile(in, zOut, prefix+vPath, entry.getTime());
                         }
                     }
-                    else if (fullpath.length() > 0) {
-                        zipFile(in, zOut, fullpath, entry.getTime());
-                    }
                 }
             }
         } finally {