=== modified file 'lisp/ChangeLog'
--- lisp/ChangeLog	2012-12-19 13:01:16 +0000
+++ lisp/ChangeLog	2013-01-24 20:29:45 +0000
@@ -1,3 +1,10 @@
+2013-01-24  Oleksandr Gavenko  <gavenkoa@gmail.com>
+
+	* ert.el (ert--explain-format-atom): Delete formating into
+	character due to performance issue on attempts to find font glyph
+	for rare used character and impossibility handle negative or large
+	numbers.
+
 2012-12-19  Michael Albinus  <michael.albinus@gmx.de>
 
 	* net/tramp-sh.el (tramp-sh-handle-file-acl): Delete empty lines

=== modified file 'lisp/emacs-lisp/ert.el'
--- lisp/emacs-lisp/ert.el	2012-11-23 03:26:09 +0000
+++ lisp/emacs-lisp/ert.el	2013-01-24 20:21:48 +0000
@@ -568,7 +568,7 @@
 (defun ert--explain-format-atom (x)
   "Format the atom X for `ert--explain-equal'."
   (cl-typecase x
-    (fixnum (list x (format "#x%x" x) (format "?%c" x)))
+    (fixnum (list x (format "#x%x" x)))
     (t x)))
 
 (defun ert--explain-equal-rec (a b)