Treat case like f()

jedi/api.py

@@ -232,7 +232,7 @@ class Script(object):
 
         context = self._module.get_context()
         scopes = set()
-        lower_priority_operators = ('(', ',')
+        lower_priority_operators = ('()', '(', ',')
         """Operators that could hide callee."""
         if next(context) in ('class', 'def'):
             scopes = set([self._module.parser.user_scope])

test/regression.py

@@ -122,6 +122,10 @@ class TestRegression(TestBase):
         defs = self.definition_when_in_function_call('f(1, ')
         self.assertEqual(defs[0].description, 'def f')
 
+    def test_definition_when_in_function_call_empty_paren(self):
+        defs = self.definition_when_in_function_call('f(', ')')
+        self.assertEqual(defs[0].description, 'def f')
+
     def test_function_call_signature(self):
         defs = self.definition("""
         def f(x, y=1, z='a'):