failing test

tests/test_basic.py

@@ -980,6 +980,39 @@ def test_http_error_subclass_handling(app, client):
     assert client.get('/3').data == b'apple'
 
 
+def test_errorhandler_precedence(app, client):
+    class E1(Exception):
+        pass
+
+    class E2(Exception):
+        pass
+
+    class E3(E1, E2):
+        pass
+
+    @app.errorhandler(E2)
+    def handle_e2(e):
+        return 'E2'
+
+    @app.errorhandler(Exception)
+    def handle_exception(e):
+        return 'Exception'
+
+    @app.route('/E1')
+    def raise_e1():
+        raise E1
+
+    @app.route('/E3')
+    def raise_e3():
+        raise E3
+
+    rv = client.get('/E1')
+    assert rv.data == b'Exception'
+
+    rv = client.get('/E3')
+    assert rv.data == b'E2'
+
+
 def test_trapping_of_bad_request_key_errors(app, client):
     @app.route('/fail')
     def fail():