[FIXED JENKINS-12490] auto-complete the copy new node page

changelog.html

@@ -62,6 +62,9 @@ Upcoming changes</a>
   <li class=bug>
     month should not be 0.
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-12356">issue 12356</a>)
+  <li class=bug>
+    "Create a new slave" page didn't auto-complete for copying.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-12490">issue 12490</a>)
   <li class=bug>
     Fixed a bug in the auto-overwrite of bundled plugins.
   <li class=rfe>

core/src/main/java/hudson/model/ComputerSet.java

@@ -25,6 +25,7 @@ package hudson.model;
 
 import hudson.BulkChange;
 import hudson.DescriptorExtensionList;
+import hudson.Extension;
 import hudson.Util;
 import hudson.XmlFile;
 import hudson.model.Descriptor.FormException;
@@ -59,7 +60,7 @@ import java.util.logging.Logger;
  * @author Kohsuke Kawaguchi
  */
 @ExportedBean
-public final class ComputerSet extends AbstractModelObject {
+public final class ComputerSet extends AbstractModelObject implements Describable<ComputerSet> {
     /**
      * This is the owner that persists {@link #monitors}.
      */
@@ -298,7 +299,7 @@ public final class ComputerSet extends AbstractModelObject {
             return FormValidation.error(e.getMessage());
         }
     }
-
+    
     /**
      * Accepts submission from the configuration page.
      */
@@ -333,6 +334,32 @@ public final class ComputerSet extends AbstractModelObject {
         return new Api(this);
     }
 
+    public Descriptor<ComputerSet> getDescriptor() {
+        return Jenkins.getInstance().getDescriptorOrDie(ComputerSet.class);
+    }
+
+    @Extension
+    public static class DescriptorImpl extends Descriptor<ComputerSet> {
+        @Override
+        public String getDisplayName() {
+            return "";
+        }
+
+        /**
+         * Auto-completion for the "copy from" field in the new job page.
+         */
+        public AutoCompletionCandidates doAutoCompleteCopyNewItemFrom(@QueryParameter final String value) {
+            final AutoCompletionCandidates r = new AutoCompletionCandidates();
+
+            for (Node n : Jenkins.getInstance().getNodes()) {
+                if (n.getNodeName().startsWith(value))
+                    r.add(n.getNodeName());
+            }
+
+            return r;
+        }
+    }
+
     /**
      * Just to force the execution of the static initializer.
      */