--- a/Lib/unittest/util.py	Sat Jun 25 15:03:52 2011 +0200
+++ b/Lib/unittest/util.py	Sun Jun 26 17:12:16 2011 +0200
@@ -5,14 +5,31 @@
 __unittest = True
 
 _MAX_LENGTH = 80
-def safe_repr(obj, short=False):
+def safe_repr(obj, short=False, max_length=None):
     try:
         result = repr(obj)
     except Exception:
         result = object.__repr__(obj)
-    if not short or len(result) < _MAX_LENGTH:
+
+    len_result = len(result)
+    truncate_size = max_length or _MAX_LENGTH
+    if not short or len_result <= truncate_size:
         return result
-    return result[:_MAX_LENGTH] + ' [truncated]...'
+
+    if truncate_size <= _MAX_LENGTH:
+        result = result[:truncate_size]
+    else:
+        #  0         _MAX_LENGTH     truncate_size    len(result)
+        #  begin                        trunc             end
+        #  <----------------------------------------------->
+        #  begin   ...   trunc
+        #  <-------------->
+        result = (result[:_MAX_LENGTH // 2] + '...' +
+                  result[-_MAX_LENGTH // 2:truncate_size])
+
+    if truncate_size < len_result:
+        return result + ' [truncated]...'
+    return result
 
 def strclass(cls):
     return "%s.%s" % (cls.__module__, cls.__name__)