not sure why, but otherwise a directory creation fails.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@11605 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/FilePath.java

@@ -294,6 +294,7 @@ public final class FilePath implements Serializable {
     public void unzip(FilePath target) throws IOException, InterruptedException {
         target.act(new FileCallable<Void>() {
             public Void invoke(File dir, VirtualChannel channel) throws IOException {
+                dir = dir.getAbsoluteFile();    // without absolutization, getParentFile below seems to fail
                 ZipInputStream zip = new ZipInputStream(FilePath.this.read());
                 java.util.zip.ZipEntry e;