--- a/lisp/ChangeLog	Mon Aug 05 17:20:16 2013 +0100
+++ b/lisp/ChangeLog	Wed Aug 21 19:02:59 2013 +0100
@@ -1,3 +1,18 @@
+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.
+
 2013-08-05  Aidan Kehoe  <kehoea@parhasard.net>
 
 	* isearch-mode.el (isearch-pre-command-hook):

--- a/lisp/bytecomp.el	Mon Aug 05 17:20:16 2013 +0100
+++ b/lisp/bytecomp.el	Wed Aug 21 19:02:59 2013 +0100
@@ -4111,6 +4111,7 @@
 (byte-defop-compiler-1 integerp)
 (byte-defop-compiler-1 eql)
 (byte-defop-compiler-1 fillarray)
+(byte-defop-compiler-1 gensym)
 
 (defun byte-compile-progn (form)
   (byte-compile-body-do-effect (cdr form)))
@@ -4399,6 +4400,19 @@
       (byte-compile-out-tag donetag))
     (byte-compile-subr-wrong-args form 2)))
 
+(defun byte-compile-gensym (form)
+  (when for-effect
+    (byte-compile-warn "%s: %S: called for-effect, unlikely to be useful"
+                       (car form) form))
+  (when (and (cdr form) (cl-const-expr-p (nth 1 form))
+             (not (typep (cl-const-expr-val (nth 1 form) '#:not-constant)
+                         '(or string integer))))
+    (byte-compile-warn "%s: %s: only strings and integers valid for ARG"
+                       (car form)
+                       (let ((print-readably t))
+                         (prin1-to-string (nth 1 form)))))
+  (byte-compile-normal-call form))
+
 ;;(byte-defop-compiler-1 /= byte-compile-negated)
 (byte-defop-compiler-1 atom byte-compile-negated)
 (byte-defop-compiler-1 nlistp byte-compile-negated)

--- a/lisp/window-xemacs.el	Mon Aug 05 17:20:16 2013 +0100
+++ b/lisp/window-xemacs.el	Wed Aug 21 19:02:59 2013 +0100
@@ -355,8 +355,8 @@
 to them in the restored configuration.  It does not include entries for
 windows that have not changed identity.
 Does not restore the value of point in current buffer."
-  (let ((window-config (gensym 'window-config))
-	(mapping (gensym 'mapping)))
+  (let ((window-config (gensym "window-config"))
+	(mapping (gensym "mapping")))
     `(let ((,window-config (current-window-configuration))
 	   (,mapping))
       (unwind-protect

--- 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)