Index: src/main/java/hudson/plugins/perforce/PerforceSCM.java
===================================================================
--- src/main/java/hudson/plugins/perforce/PerforceSCM.java	(revision 31175)
+++ src/main/java/hudson/plugins/perforce/PerforceSCM.java	(working copy)
@@ -925,8 +925,18 @@
         
         // Ensure that the root is appropriate (it might be wrong if the user
         // created it, or if we previously built on another node).
-
-        String localPath = getLocalPathName(workspace, launcher.isUnix());
+        
+        // Both launcher and workspace can be null if requiresWorkspaceForPolling returns true
+        // So provide 'reasonable' default values.
+        boolean isunix = true;
+        if (launcher!= null)
+        	isunix=launcher.isUnix();
+        
+        String localPath = p4workspace.getRoot();
+        
+        if (workspace!=null)
+        	localPath = getLocalPathName(workspace, isunix);
+        
         if (!localPath.equals(p4workspace.getRoot()) && !dontChangeRoot && !dontUpdateClient) {
             log.println("Changing P4 Client Root to: " + localPath);
             forceSync = true;
@@ -1769,7 +1779,16 @@
     }
 
     @Override public boolean requiresWorkspaceForPolling() {
-        return true;
+	// If slaveClientNameFormat is empty - not using a host specific name, so can always
+	// use 'master' to calculate poll changes without a local workspace
+	// This allows slaves to be thrown away and still allow polling to work
+
+	if(getSlaveClientNameFormat().equals("${basename}")) {
+		Logger.getLogger(PerforceSCM.class.getName()).info(
+			"No SlaveClientName supplied - assuming shared clientname - so no Workspace required for Polling");
+		return false;
+	}
+      return true;
     }
 
 }
Index: src/main/webapp/help/clientNameFormat.html
===================================================================
--- src/main/webapp/help/clientNameFormat.html	(revision 31175)
+++ src/main/webapp/help/clientNameFormat.html	(working copy)
@@ -11,4 +11,6 @@
 </ul>
   </p>
   <p>The recommended default value is "${basename}-${hash}" (without quotes).</p>
+ <p> When set to the default ${basename} is used, and this also enables polling to occur on the master</p>
+<p>This allows polling to occur without the last slave to be online</p>
 </div>