Fixed a possible NPE in <tt>Hudson.removeNode</tt>

    (<a href="http://www.nabble.com/problems-adding-deleting-nodes-p24999793.html">report</a>)


git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@20812 71c3de6d-444a-0410-be80-ed276b4c234a

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

@@ -87,6 +87,7 @@ import hudson.slaves.Cloud;
 import hudson.slaves.DumbSlave;
 import hudson.slaves.NodeDescriptor;
 import hudson.slaves.NodeProvisioner;
+import hudson.slaves.OfflineCause;
 import hudson.tasks.BuildWrapper;
 import hudson.tasks.Builder;
 import hudson.tasks.DynamicLabeler;
@@ -1373,7 +1374,9 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
      * Removes a {@link Node} from Hudson.
      */
     public synchronized void removeNode(Node n) throws IOException {
-        n.toComputer().disconnect();
+        Computer c = n.toComputer();
+        if (c!=null)
+            c.disconnect(OfflineCause.create(Messages._Hudson_NodeBeingRemoved()));
 
         ArrayList<Node> nl = new ArrayList<Node>(this.slaves);
         nl.remove(n);

core/src/main/resources/hudson/model/Messages.properties

@@ -78,6 +78,7 @@ Hudson.JobAlreadyExists=A job already exists with the name ''{0}''
 Hudson.NoJavaInPath=java is not in your PATH. Maybe you need to <a href=''{0}/configure''>configure JDKs</a>?
 Hudson.NoName=No name is specified
 Hudson.NoSuchDirectory=No such directory: {0}
+Hudson.NodeBeingRemoved=Node is being removed
 Hudson.NotADirectory={0} is not a directory
 Hudson.NotAPlugin={0} is not a Hudson plugin
 Hudson.NotJDKDir={0} doesn''t look like a JDK directory