Warn about non-string non-integer ARG to #'gensym, bytecomp.el. lisp/ChangeLog addition: 2013-08-21 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el: * bytecomp.el (gensym): * bytecomp.el (byte-compile-gensym): New. Warn that gensym called in a for-effect context is unlikely to be useful. Warn about non-string non-integer ARGs, this is incorrect. Am not changing the function to error with same, most code that makes the mistake is has no problems, which is why it has survived so long. * window-xemacs.el (save-window-excursion/mapping): * window.el (save-window-excursion): Call #'gensym with a string, not a symbol.

--- a/lisp/window.el	Mon Aug 05 17:20:16 2013 +0100
+++ b/lisp/window.el	Wed Aug 21 19:02:59 2013 +0100
@@ -202,7 +202,7 @@
 Restores which buffer appears in which window, where display starts,
 as well as the current buffer.
 Does not restore the value of point in current buffer."
-  (let ((window-config (gensym 'window-config)))
+  (let ((window-config (gensym "window-config")))
     `(let ((,window-config (current-window-configuration)))
       (unwind-protect
 	  (progn ,@body)