#877 - reencoding causes typeerrors on python2

Author: RonnyPfannschmidt

_pytest/assertion/util.py

@@ -130,13 +130,15 @@ def assertrepr_compare(config, op, left, right):
     left_repr = py.io.saferepr(left, maxsize=int(width/2))
     right_repr = py.io.saferepr(right, maxsize=width-len(left_repr))
 
-    # the reencoding is needed for python2 repr
-    # with non-ascii characters (see isssue 877)
-    summary = u('%s %s %s') % (
-        u(left_repr, 'utf-8', 'replace'),
-        op,
-        u(right_repr, 'utf-8', 'replace'),
-    )
+    # the re-encoding is needed for python2 repr
+    # with non-ascii characters (see issue 877)
+    def ecu(s):
+        try:
+            return u(s, 'utf-8', 'replace')
+        except TypeError:
+            return s
+
+    summary = u('%s %s %s') % (ecu(left_repr), op, ecu(right_repr))
 
     issequence = lambda x: (isinstance(x, (list, tuple, Sequence))
                             and not isinstance(x, basestring))