[pypy-commit] pypy default: Issue 2551: Struct should be initialized in __init__, not __new__

[amauryfa]

Author: Amaury Forgeot d'Arc <amauryfa at gmail.com>
Branch: 
Changeset: r91189:f452cdf49d49
Date: 2017-05-04 00:23 +0200
http://bitbucket.org/pypy/pypy/changeset/f452cdf49d49/

Log:	Issue 2551: Struct should be initialized in __init__, not __new__

diff --git a/pypy/module/struct/interp_struct.py b/pypy/module/struct/interp_struct.py
--- a/pypy/module/struct/interp_struct.py
+++ b/pypy/module/struct/interp_struct.py
@@ -115,16 +115,17 @@
 class W_Struct(W_Root):
     _immutable_fields_ = ["format", "size"]
 
-    def __init__(self, space, format):
+    format = ""
+    size = -1
+
+    def descr__new__(space, w_subtype, __args__):
+        return space.allocate_instance(W_Struct, w_subtype)
+
+    @unwrap_spec(format='text')
+    def descr__init__(self, space, format):
         self.format = format
         self.size = _calcsize(space, format)
 
-    @unwrap_spec(format='text')
-    def descr__new__(space, w_subtype, format):
-        self = space.allocate_instance(W_Struct, w_subtype)
-        W_Struct.__init__(self, space, format)
-        return self
-
     def descr_pack(self, space, args_w):
         return pack(space, jit.promote_string(self.format), args_w)
 
@@ -141,6 +142,7 @@
 
 W_Struct.typedef = TypeDef("Struct",
     __new__=interp2app(W_Struct.descr__new__.im_func),
+    __init__=interp2app(W_Struct.descr__init__),
     format=interp_attrproperty("format", cls=W_Struct, wrapfn="newbytes"),
     size=interp_attrproperty("size", cls=W_Struct, wrapfn="newint"),
 
diff --git a/pypy/module/struct/test/test_struct.py b/pypy/module/struct/test/test_struct.py
--- a/pypy/module/struct/test/test_struct.py
+++ b/pypy/module/struct/test/test_struct.py
@@ -429,6 +429,14 @@
         assert s.unpack(s.pack(42)) == (42,)
         assert s.unpack_from(memoryview(s.pack(42))) == (42,)
 
+    def test_struct_subclass(self):
+        class S(self.struct.Struct):
+            def __init__(self):
+                assert self.size == -1
+                super(S, self).__init__('c')
+                assert self.size == 1
+        assert S().unpack('a') == ('a',)
+
     def test_overflow(self):
         raises(self.struct.error, self.struct.pack, 'i', 1<<65)