Index: model/AbstractProject.java
===================================================================
RCS file: /cvs/hudson/hudson/main/core/src/main/java/hudson/model/AbstractProject.java,v
retrieving revision 1.84
diff -u -r1.84 AbstractProject.java
--- model/AbstractProject.java	10 Feb 2008 01:37:30 -0000	1.84
+++ model/AbstractProject.java	22 Feb 2008 17:25:55 -0000
@@ -582,19 +591,24 @@
         }
 
         try {
-            FilePath workspace = getWorkspace();
-            if(workspace==null) {
-                // workspace offline. build now, or nothing will ever be built
-                listener.getLogger().println(Messages.AbstractProject_WorkspaceOffline());
-                return true;
-            }
-            if(!workspace.exists()) {
-                // no workspace. build now, or nothing will ever be built
-                listener.getLogger().println(Messages.AbstractProject_NoWorkspace());
-                return true;
-            }
+        	FilePath workspace = getWorkspace();
+        	if (scm.requiresWorkspaceForPolling()) {
+        		if(workspace==null) {
+        			// workspace offline. build now, or nothing will ever be built
+        			listener.getLogger().println("Workspace is offline.");
+        			listener.getLogger().println("Scheduling a new build to get a workspace.");
+        			return true;
+        		}
+        		if(!workspace.exists()) {
+        			// no workspace. build now, or nothing will ever be built
+        			listener.getLogger().println("No workspace is available, so can't check for updates.");
+        			listener.getLogger().println("Scheduling a new build to get a workspace.");
+        			return true;
+        		}
+        	}
 
-            return scm.pollChanges(this, workspace.createLauncher(listener), workspace, listener );
+        	Launcher launcher = workspace != null ? workspace.createLauncher(listener) : null;
+            return scm.pollChanges(this, launcher, workspace, listener );
         } catch (AbortException e) {
             listener.fatalError(Messages.AbstractProject_Aborted());
             return false;
Index: scm/SCM.java
===================================================================
RCS file: /cvs/hudson/hudson/main/core/src/main/java/hudson/scm/SCM.java,v
retrieving revision 1.26
diff -u -r1.26 SCM.java
--- scm/SCM.java	13 Jan 2008 22:05:48 -0000	1.26
+++ scm/SCM.java	26 Jan 2008 19:10:07 -0000
@@ -80,6 +80,13 @@
     public boolean supportsPolling() {
         return true;
     }
+    
+    /**
+     * Returns true if this SCM requires a checked out workspace for polling
+     */
+    public boolean requiresWorkspaceForPolling() {
+    	return true;
+    }
 
     /**
      * Checks if there has been any changes to this module in the repository.
Index: scm/SubversionSCM.java
===================================================================
RCS file: /cvs/hudson/hudson/main/core/src/main/java/hudson/scm/SubversionSCM.java,v
retrieving revision 1.125
diff -u -r1.125 SubversionSCM.java
--- scm/SubversionSCM.java	8 Feb 2008 02:29:07 -0000	1.125
+++ scm/SubversionSCM.java	9 Feb 2008 08:52:17 -0000
@@ -56,6 +56,7 @@
 import org.tmatesoft.svn.core.wc.SVNClientManager;
 import org.tmatesoft.svn.core.wc.SVNInfo;
 import org.tmatesoft.svn.core.wc.SVNRevision;
+import org.tmatesoft.svn.core.wc.SVNStatus;
 import org.tmatesoft.svn.core.wc.SVNUpdateClient;
 import org.tmatesoft.svn.core.wc.SVNWCClient;
 import org.tmatesoft.svn.core.wc.SVNWCUtil;
@@ -1356,4 +1382,12 @@
 
         ch.ethz.ssh2.log.Logger.logLevel = 100;
     }
+
+    /**
+     * Polling can happen on the master and does not require a workspace.
+     */
+	@Override
+	public boolean requiresWorkspaceForPolling() {
+		return false;
+	}
 }