Fix ClassVars and add tests

jedi/evaluate/context/typing.py

@@ -166,7 +166,7 @@ class TypingContextWithIndex(_WithIndexBase):
             return ContextSet(self._index_context)
         elif string_name == 'ClassVar':
             # For now don't do anything here, ClassVars are always used.
-            return self._context.execute_annotation()
+            return self._index_context.execute_annotation()
 
         cls = globals()[string_name]
         return ContextSet(cls(self._name, self._index_context, self._context_of_index))

test/completion/pep0526_variables.py

@@ -36,3 +36,18 @@ char: str
 for char in NOT_DEFINED:
     #? str()
     char
+
+
+class Foo():
+    bar: int
+    baz: typing.ClassVar[str]
+
+
+#? int()
+Foo.bar
+#? int()
+Foo().bar
+#? str()
+Foo.baz
+#? str()
+Foo().baz