Accessing workspace no longer throws NPE if last used slave is offline (issue #1657)

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@9069 71c3de6d-444a-0410-be80-ed276b4c234a

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

@@ -924,7 +924,7 @@ public abstract class AbstractProject<P extends AbstractProject<P,R>,R extends A
     public void doWs( StaplerRequest req, StaplerResponse rsp ) throws IOException, ServletException, InterruptedException {
         checkPermission(AbstractProject.WORKSPACE);
         FilePath ws = getWorkspace();
-        if(!ws.exists()) {
+        if ((ws == null) || (!ws.exists())) {
             // if there's no workspace, report a nice error message
             req.getView(this,"noWorkspace.jelly").forward(req,rsp);
         } else {