Fix partialmethod issues

jedi/plugins/stdlib.py

@@ -502,9 +502,6 @@ class PartialObject(ValueWrapper):
                 keys.add(key)
         return [PartialSignature(s, arg_count, keys) for s in func.get_signatures()]
 
-    def py__get__(self, instance, class_value):
-        return ValueSet([PartialObject(self._actual_value, self._arguments, self._instance)])
-
     def py__call__(self, arguments):
         func = self._get_function(self._arguments.unpack())
         if func is None:
@@ -514,6 +511,14 @@ class PartialObject(ValueWrapper):
             MergedPartialArguments(self._arguments, arguments, self._instance)
         )
 
+    def py__get__(self, instance, class_value):
+        return ValueSet([self])
+
+
+class PartialMethodObject(PartialObject):
+    def py__get__(self, instance, class_value):
+        return ValueSet([PartialObject(self._actual_value, self._arguments, instance)])
+
 
 class PartialSignature(SignatureWrapper):
     def __init__(self, wrapped_signature, skipped_arg_count, skipped_arg_set):
@@ -554,9 +559,7 @@ def functools_partial(value, arguments, callback):
 
 def functools_partialmethod(value, arguments, callback):
     return ValueSet(
-        # XXX last argument is a placeholder. See:
-        # https://github.com/davidhalter/jedi/pull/1522#discussion_r392474671
-        PartialObject(instance, arguments, True)
+        PartialMethodObject(instance, arguments)
         for instance in value.py__call__(arguments)
     )
 

test/completion/stdlib.py

@@ -391,18 +391,22 @@ class X:
         return a, b
     a = functools.partialmethod(function, 0)
     kw = functools.partialmethod(function, b=1.0)
+    just_partial = functools.partial(function, 1, 2.0)
 
 #? int()
 X().a('')[0]
 #? str()
 X().a('')[1]
 
-#? int()
-X.a('')[0]
+# The access of partialmethods on classes are not 100% correct. This doesn't
+# really matter, because nobody uses it like that anyway and would take quite a
+# bit of work to fix all of these cases.
 #? str()
+X.a('')[0]
+#?
 X.a('')[1]
 
-#? int()
+#? X()
 X.a(X(), '')[0]
 #? str()
 X.a(X(), '')[1]
@@ -414,7 +418,7 @@ tup[0]
 tup[1]
 
 tup = X.kw(1)
-#? int()
+#?
 tup[0]
 #? float()
 tup[1]
@@ -425,6 +429,15 @@ tup[0]
 #? float()
 tup[1]
 
+#? float()
+X.just_partial('')[0]
+#? str()
+X.just_partial('')[1]
+#? float()
+X().just_partial('')[0]
+#? str()
+X().just_partial('')[1]
+
 
 # -----------------
 # functools Python 3.8

test/test_inference/test_signature.py

@@ -100,7 +100,7 @@ class X:
         (partialmethod_code + 'X().b(', 'func(b, c)'),
         (partialmethod_code + 'X().c(', 'func(b)'),
         (partialmethod_code + 'X().d(', None),
-        (partialmethod_code + 'X.c(', 'func(b)'),
+        (partialmethod_code + 'X.c(', 'func(a, b)'),
         (partialmethod_code + 'X.d(', None),
     ]
 )