Add support for inferring methods masquerading as others for the binop protocols.

2 files changed, 16 insertions, 1 deletions

diff --git a/astroid/inference.py b/astroid/inference.py
index 3864f43..fda5f2e 100644
--- a/astroid/inference.py
+++ b/astroid/inference.py
@@ -429,7 +429,8 @@ def _is_not_implemented(const):
 def  _invoke_binop_inference(instance, op, other, context, method_name):
     """Invoke binary operation inference on the given instance."""
     method = instance.getattr(method_name)[0]
-    return instance.infer_binary_op(op, other, context, method)
+    inferred = next(method.infer(context=context))
+    return instance.infer_binary_op(op, other, context, inferred)
 
 def _aug_op(instance, op, other, context, reverse=False):
     """Get an inference callable for an augmented binary operation."""
diff --git a/astroid/tests/unittest_inference.py b/astroid/tests/unittest_inference.py
index f8fa0dd..87e6993 100644
--- a/astroid/tests/unittest_inference.py
+++ b/astroid/tests/unittest_inference.py
@@ -2644,6 +2644,20 @@ class InferenceTest(resources.SysPathSetup, unittest.TestCase):
             inferred = next(rest.infer())
             self.assertEqual(inferred, YES)
 
+    def test_special_method_masquerading_as_another(self):
+        ast_node = test_utils.extract_node('''
+        class Info(object):
+            def __add__(self, other):
+                return "lala"
+            __or__ = __add__
+
+        f = Info()
+        f | Info() #@
+        ''')
+        inferred = next(ast_node.infer())
+        self.assertIsInstance(inferred, nodes.Const)
+        self.assertEqual(inferred.value, "lala")
+
 
 class GetattrTest(unittest.TestCase):