Fixed bug with nil project.

ChangeLog

@@ -1,5 +1,7 @@
 2008-03-10  Carsten Dominik  <dominik@science.uva.nl>
 
+	* org-publish.el (org-publish-get-files): Protect against empty p.
+
 	* org.el (org-ctrl-c-star): Implement a missing branch in the
 	decision tree.
 

org-publish.el

@@ -379,7 +379,7 @@ If NO-EXCLUSION is non-nil, don't exclude files."
     (mapc
      (lambda(p)
        (let* ((exclude (plist-get (cdr p) :exclude))
-	      (files (org-publish-get-base-files p exclude)))
+	      (files (and p (org-publish-get-base-files p exclude))))
 	 ;; add all files from this project
 	 (mapc (lambda(f)
 		 (add-to-list 'all-files