Fix inheritance unification

trans/transpiler/phases/typing/types.py

@@ -40,6 +40,9 @@ class BaseType(ABC):
             for p in cur.get_parents():
                 queue.put(p)
 
+    def inherits_from(self, other: "BaseType") -> bool:
+        return other in self.iter_hierarchy_recursive()
+
     def resolve(self) -> "BaseType":
         return self
 
@@ -219,25 +222,27 @@ class TypeOperator(BaseType, ABC):
             return other.unify_internal(self)
         if self.is_protocol and not other.is_protocol:
             return other.matches_protocol(self)  # TODO: doesn't print the correct type in the error message
-        if len(self.args) < len(other.args):
-            return other.unify_internal(self)
         assert self.is_protocol == other.is_protocol
-        if type(self) != type(other):
-            for parent in other.get_parents():
-                try:
-                    self.unify(parent)
-                except TypeMismatchError:
-                    pass
-                else:
-                    return
-            for parent in self.get_parents():
-                try:
-                    parent.unify(other)
-                except TypeMismatchError:
-                    pass
-                else:
+        if type(self) != type(other): # and ((TY_NONE not in {self, other}) or isinstance(({self, other} - {TY_NONE}).pop(), UnionType)):
+            if self.inherits_from(other) or other.inherits_from(self):
                 return
+            # for parent in other.get_parents():
+            #     try:
+            #         self.unify(parent)
+            #     except TypeMismatchError:
+            #         pass
+            #     else:
+            #         return
+            # for parent in self.get_parents():
+            #     try:
+            #         parent.unify(other)
+            #     except TypeMismatchError:
+            #         pass
+            #     else:
+            #         return
             raise TypeMismatchError(self, other, TypeMismatchKind.DIFFERENT_TYPE)
+        if len(self.args) < len(other.args):
+            return other.unify_internal(self)
         if len(self.args) == 0:
             if self.name != other.name:
                 raise TypeMismatchError(self, other, TypeMismatchKind.DIFFERENT_TYPE)