Detect dynamic code explicitly in filter_traceback

_pytest/python.py

@@ -49,10 +49,14 @@ def _has_positional_arg(func):
 
 
 def filter_traceback(entry):
-    # ensure entry.path is always a py.path.local object
+    # entry.path might sometimes return a str() object when the entry
+    # points to dynamically generated code
     # see https://bitbucket.org/pytest-dev/py/issues/71
-    path = py.path.local(entry.path)
-    return path != cutdir1 and not path.relto(cutdir2)
+    raw_filename = entry.frame.code.raw.co_filename
+    is_generated = '<' in raw_filename and '>' in raw_filename
+    if is_generated:
+        return False
+    return entry.path != cutdir1 and not entry.path.relto(cutdir2)
 
 
 def get_real_func(obj):

testing/python/collect.py

@@ -778,7 +778,7 @@ class TestTracebackCutting:
 
         tb = py.code.Traceback(tb)
         assert isinstance(tb[-1].path, str)  # symptom of the py.code bug
-        assert filter_traceback(tb[-1])
+        assert not filter_traceback(tb[-1])
 
 
 class TestReportInfo: