Fix default_factory for inherited dataclass

mypyc/irbuild/classdef.py

@@ -760,7 +760,6 @@ def find_attr_initializers(
     if cls.builtin_base:
         return set(), []
 
-    cls_type = dataclass_type(cdef)
     attrs_with_defaults: set[str] = set()
     default_assignments: list[tuple[AssignmentStmt, str]] = []
 
@@ -774,10 +773,11 @@ def find_attr_initializers(
         info_ir = builder.mapper.type_to_ir.get(info)
         if info_ir is None:
             continue
+        info_cls_type = dataclass_type(info.defn)
         for stmt in info.defn.defs.body:
             if not isinstance(stmt, AssignmentStmt):
                 continue
-            name = default_attr_name(stmt, info_ir, cls_type)
+            name = default_attr_name(stmt, info_ir, info_cls_type)
             if name is None:
                 continue
             attrs_with_defaults.add(name)

mypyc/test-data/run-python37.test

@@ -74,8 +74,15 @@ class Person5:
     friends: Set[str] = field(default_factory=set)
     parents: FrozenSet[str] = frozenset()
 
+@dataclass
+class HasFactoryDefault:
+    x: dict[str, int] = field(default_factory=dict)
+
+class InheritsDataclassInit(HasFactoryDefault):
+    pass
+
 [file other.py]
-from native import Person1, Person1b, Person2, Person3, Person4, Person5, testBool
+from native import Person1, Person1b, Person2, Person3, Person4, Person5, testBool, InheritsDataclassInit
 i1 = Person1(age = 5, name = 'robot')
 assert i1.age == 5
 assert i1.name == 'robot'
@@ -125,6 +132,9 @@ assert Person1.__annotations__ == {'age': int, 'name': str}
 assert Person2.__annotations__ == {'age': int, 'name': str}
 assert Person5.__annotations__ == {'weight': float, 'friends': set,
                                        'parents': frozenset}
+v = InheritsDataclassInit()
+assert isinstance(v.x, dict)
+assert v.x == {}
 
 [file driver.py]
 import sys