Make sure py__get__ is defined on all values

Also define matches_signature on all signatures, there's definitely cases where that might be called

jedi/inference/base_value.py

@@ -239,6 +239,10 @@ class Value(HelperValueMixin, BaseValue):
         """
         return NO_VALUES
 
+    def py__get__(self, instance, class_value):
+        debug.warning("No __get__ defined on %s", self)
+        return ValueSet([self])
+
     def get_qualified_names(self):
         # Returns Optional[Tuple[str, ...]]
         return None

jedi/inference/signature.py

@@ -56,6 +56,9 @@ class AbstractSignature(_SignatureMixin):
     def bind(self, value):
         raise NotImplementedError
 
+    def matches_signature(self, arguments):
+        return True
+
     def __repr__(self):
         if self.value is self._function_value:
             return '<%s: %s>' % (self.__class__.__name__, self.value)

jedi/inference/value/instance.py

@@ -17,7 +17,7 @@ from jedi.inference.arguments import ValuesArguments, TreeArgumentsWrapper
 from jedi.inference.value.function import \
     FunctionValue, FunctionMixin, OverloadedFunctionValue, \
     BaseFunctionExecutionContext, FunctionExecutionContext
-from jedi.inference.value.klass import apply_py__get__, ClassFilter
+from jedi.inference.value.klass import ClassFilter
 from jedi.inference.value.dynamic_arrays import get_dynamic_array_instance
 
 
@@ -263,7 +263,7 @@ class _BaseTreeInstance(AbstractInstanceValue):
 
         return ValueSet.from_sets(name.infer().execute(arguments) for name in names)
 
-    def py__get__(self, obj, class_value):
+    def py__get__(self, instance, class_value):
         """
         obj may be None.
         """
@@ -271,9 +271,9 @@ class _BaseTreeInstance(AbstractInstanceValue):
         # `method` is the new parent of the array, don't know if that's good.
         names = self.get_function_slot_names(u'__get__')
         if names:
-            if obj is None:
+            if instance is None:
-                obj = compiled.builtin_from_name(self.inference_state, u'None')
+                instance = compiled.builtin_from_name(self.inference_state, u'None')
-            return self.execute_function_slots(names, obj, class_value)
+            return self.execute_function_slots(names, instance, class_value)
         else:
             return ValueSet([self])
 
@@ -320,7 +320,8 @@ class TreeInstance(_BaseTreeInstance):
         for signature in self.class_value.py__getattribute__('__init__').get_signatures():
             # Just take the first result, it should always be one, because we
             # control the typeshed code.
-            if not signature.matches_signature(args):
+            if not signature.matches_signature(args) \
+                    or signature.value.tree_node is None:
                 # First check if the signature even matches, if not we don't
                 # need to infer anything.
                 continue
@@ -481,7 +482,7 @@ class LazyInstanceClassName(object):
     @iterator_to_value_set
     def infer(self):
         for result_value in self._class_member_name.infer():
-            for c in apply_py__get__(result_value, self._instance, self._instance.py__class__()):
+            for c in result_value.py__get__(self._instance, self._instance.py__class__()):
                 yield c
 
     def __getattr__(self, name):

jedi/inference/value/klass.py

@@ -53,16 +53,6 @@ from jedi.inference.value.function import FunctionAndClassBase
 from jedi.plugins import plugin_manager
 
 
-def apply_py__get__(value, instance, class_value):
-    try:
-        method = value.py__get__
-    except AttributeError:
-        yield value
-    else:
-        for descriptor_value in method(instance, class_value):
-            yield descriptor_value
-
-
 class ClassName(TreeNameDefinition):
     def __init__(self, class_value, tree_name, name_context, apply_decorators):
         super(ClassName, self).__init__(class_value.as_context(), tree_name)
@@ -79,9 +69,7 @@ class ClassName(TreeNameDefinition):
 
         for result_value in inferred:
             if self._apply_decorators:
-                for c in apply_py__get__(result_value,
+                for c in result_value.py__get__(instance=None, class_value=self._class_value):
-                                         instance=None,
-                                         class_value=self._class_value):
                     yield c
             else:
                 yield result_value

jedi/plugins/stdlib.py

@@ -335,7 +335,7 @@ def builtins_isinstance(objects, types, arguments, inference_state):
 
 
 class StaticMethodObject(ValueWrapper):
-    def py__get__(self, instance, klass):
+    def py__get__(self, instance, class_value):
         return ValueSet([self._wrapped_value])