Fix Memory Leak Caused By Wrong Limited API Default

When a type has nullptr as tp_dealloc, there apply different defaults.

Static types had object_dealloc as default, while new heaptypes
created with type_new have subtype_dealloc as default.

A problem was now that PyType_FromSpec also has
subtype_dealloc as default. But that is wrong, because a type that
was written with the static type approach is already written with
object_dealloc in mind and takes somehow care about further issues
with that type.

When we now convert this type and suddenly use subtype_dealloc
instead of object_dealloc, things get pretty wrong.

Finding that out was pretty hard and took quite long to understand.

The fix was then very easy and is the best proof:
Replacing our former (wrong) solution of supplying an
SbkDummyDealloc with a function object_dealloc works perfectly,
and the leakage completely vanished.

The documentation now is also corrected.

Task-number: PYSIDE-832
Change-Id: Ifc20c28172eb5663cd5e60dac52e0a43acfb626c
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

1 files changed, 1 insertions, 1 deletions

diff --git a/sources/shiboken2/generator/shiboken2/cppgenerator.cpp b/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
index b0d778231..9e1d6926e 100644
--- a/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
+++ b/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
@@ -3704,7 +3704,7 @@ void CppGenerator::writeClassDefinition(QTextStream &s,
     if (metaClass->isNamespace() || metaClass->hasPrivateDestructor()) {
         tp_dealloc = metaClass->hasPrivateDestructor() ?
                      QLatin1String("SbkDeallocWrapperWithPrivateDtor") :
-                     QLatin1String("SbkDummyDealloc /* PYSIDE-595: Prevent replacement of \"0\" with subtype_dealloc. */");
+                     QLatin1String("object_dealloc /* PYSIDE-832: Prevent replacement of \"0\" with subtype_dealloc. */");
         tp_init = QLatin1String("0");
     } else {
         QString deallocClassName;