Fix self type check

kreathon · kreathon · commit 431d722a745a · 2024-05-24T18:16:44.000+02:00
diff --git a/mypy/subtypes.py b/mypy/subtypes.py
@@ -1927,7 +1927,7 @@ def restrict_subtype_away(t: Type, s: Type) -> Type:
             new_items = [
                 restrict_subtype_away(item, s)
                 for item in p_t.relevant_items()
-                if isinstance(item, UnionType) or not covers_type(item, s)
+                if isinstance(get_proper_type(item), UnionType) or not covers_type(item, s)
             ]
         return UnionType.make_union(new_items)
     elif covers_type(t, s):

Original file line number	Diff line number	Diff line change
`@@ -1927,7 +1927,7 @@ def restrict_subtype_away(t: Type, s: Type) -> Type:`
`1927`	`1927`	`new_items = [`
`1928`	`1928`	`restrict_subtype_away(item, s)`
`1929`	`1929`	`for item in p_t.relevant_items()`
`1930`		`- if isinstance(item, UnionType) or not covers_type(item, s)`
	`1930`	`+ if isinstance(get_proper_type(item), UnionType) or not covers_type(item, s)`
`1931`	`1931`	`]`
`1932`	`1932`	`return UnionType.make_union(new_items)`
`1933`	`1933`	`elif covers_type(t, s):`