fix for issue615: _format_boolop must escape %

fix test for issue615: expression must eval False

--HG--
branch : format_boolop_percent6

AUTHORS

@@ -45,3 +45,4 @@ Andy Freeland
 Trevor Bekolay
 David Mohr
 Nicolas Delaby
+Tom Viner

_pytest/assertion/rewrite.py

@@ -382,7 +382,12 @@ def _should_repr_global_name(obj):
     return not hasattr(obj, "__name__") and not py.builtin.callable(obj)
 
 def _format_boolop(explanations, is_or):
-    return "(" + (is_or and " or " or " and ").join(explanations) + ")"
+    explanation = "(" + (is_or and " or " or " and ").join(explanations) + ")"
+    if py.builtin._istext(explanation):
+        t = py.builtin.text
+    else:
+        t = py.builtin.bytes
+    return explanation.replace(t('%'), t('%%'))
 
 def _call_reprcompare(ops, results, expls, each_obj):
     for i, res, expl in zip(range(len(ops)), results, expls):

testing/test_assertrewrite.py

@@ -270,15 +270,13 @@ class TestAssertionRewrite:
             assert not 5 % 4
         assert getmsg(f) == "assert not (5 % 4)"
 
-    @pytest.mark.xfail(reason='unfixed')
-    def test_and_or_percent(self):
-        # issue 615 - ValueError on compound assert with percent
+    def test_boolop_percent(self):
         def f():
-            assert 3 % 2 or False
-        assert getmsg(f) == "assert (3 % 2) or False"
+            assert 3 % 2 and False
+        assert getmsg(f) == "assert ((3 % 2) and False)"
         def f():
-            assert True and 7 % 3
-        assert getmsg(f) == "assert True and (7 % 3)"
+            assert False or 4 % 2
+        assert getmsg(f) == "assert (False or (4 % 2))"
 
     def test_call(self):
         def g(a=42, *args, **kwargs):