[JENKINS-26476] Noting merge of #1536.

changelog.html

@@ -55,7 +55,9 @@ Upcoming changes</a>
 <!-- Record your changes in the trunk here. -->
 <div id="trunk" style="display:none"><!--=TRUNK-BEGIN=-->
 <ul class=image>
-  <li class=>
+  <li class=bug>
+    Remote <code>FilePath.chmod</code> fails with <code>ClassNotFoundException: javax.servlet.ServletException</code>.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-26476">issue 26476</a>)
 </ul>
 </div><!--=TRUNK-END=-->
 

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

@@ -1581,6 +1581,7 @@ public final class FilePath implements Serializable {
         act(new SecureFileCallable<Void>() {
             private static final long serialVersionUID = 1L;
             public Void invoke(File f, VirtualChannel channel) throws IOException {
+                // TODO first check for Java 7+ and use PosixFileAttributeView
                 _chmod(writing(f), mask);
 
                 return null;
@@ -1592,7 +1593,9 @@ public final class FilePath implements Serializable {
      * Run chmod via jnr-posix
      */
     private static void _chmod(File f, int mask) throws IOException {
-        if (Functions.isWindows())  return; // noop
+        // TODO WindowsPosix actually does something here (WindowsLibC._wchmod); should we let it?
+        // Anyway the existing calls already skip this method if on Windows.
+        if (File.pathSeparatorChar==';')  return; // noop
 
         PosixAPI.jnr().chmod(f.getAbsolutePath(),mask);
     }