apply freelist type check also when *adding* dead objects to the freelist to...

apply freelist type check also when *adding* dead objects to the freelist to make sure their eventual cleanup works correctly

Cython/Compiler/ModuleNode.py

@@ -1170,12 +1170,12 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
                 code.globalstate.use_utility_code(
                     UtilityCode.load_cached("IncludeStringH", "StringTools.c"))
                 if is_final_type:
-                    abstract_check = ''
+                    type_safety_check = ''
                 else:
-                    abstract_check = ' & ((t->tp_flags & (Py_TPFLAGS_IS_ABSTRACT | Py_TPFLAGS_HEAPTYPE)) == 0)'
+                    type_safety_check = ' & ((t->tp_flags & (Py_TPFLAGS_IS_ABSTRACT | Py_TPFLAGS_HEAPTYPE)) == 0)'
                 obj_struct = type.declaration_code("", deref=True)
                 code.putln("if (likely((%s > 0) & (t->tp_basicsize == sizeof(%s))%s)) {" % (
-                    freecount_name, obj_struct, abstract_check))
+                    freecount_name, obj_struct, type_safety_check))
                 code.putln("o = (PyObject*)%s[--%s];" % (
                     freelist_name, freecount_name))
                 code.putln("memset(o, 0, sizeof(%s));" % obj_struct)
@@ -1340,9 +1340,16 @@ class ModuleNode(Nodes.Node, Nodes.BlockNode):
                 freelist_name = scope.mangle_internal(Naming.freelist_name)
                 freecount_name = scope.mangle_internal(Naming.freecount_name)
 
+                if is_final_type:
+                    type_safety_check = ''
+                else:
+                    type_safety_check = (
+                        ' & ((Py_TYPE(o)->tp_flags & (Py_TPFLAGS_IS_ABSTRACT | Py_TPFLAGS_HEAPTYPE)) == 0)')
+
                 type = scope.parent_type
-                code.putln("if ((%s < %d) & (Py_TYPE(o)->tp_basicsize == sizeof(%s))) {" % (
-                    freecount_name, freelist_size, type.declaration_code("", deref=True)))
+                code.putln("if ((%s < %d) & (Py_TYPE(o)->tp_basicsize == sizeof(%s))%s) {" % (
+                    freecount_name, freelist_size, type.declaration_code("", deref=True),
+                    type_safety_check))
                 code.putln("%s[%s++] = %s;" % (
                     freelist_name, freecount_name, type.cast_code("o")))
                 code.putln("} else {")