Make C++ version of _Py_CAST work with 0/NULL

00383-gh-93442-make-c-version-of-_py_cast-work-with-0-null.patch

@@ -0,0 +1,82 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: "Miss Islington (bot)"
+ <31488909+miss-islington@users.noreply.github.com>
+Date: Sat, 4 Jun 2022 22:15:59 -0700
+Subject: [PATCH] 00383: gh-93442: Make C++ version of _Py_CAST work with
+ 0/NULL
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Add C++ overloads for _Py_CAST_impl() to handle 0/NULL.  This will allow
+C++ extensions that pass 0 or NULL to macros using _Py_CAST() to
+continue to compile.  Without this, you get an error like:
+
+    invalid ‘static_cast’ from type ‘int’ to type ‘_object*’
+
+The modern way to use a NULL value in C++ is to use nullptr.  However,
+we want to not break extensions that do things the old way.
+
+Co-authored-by: serge-sans-paille
+(cherry picked from commit 8bcc3fa3453e28511d04eaa0aa7d8e1a3495d518)
+
+Co-authored-by: Neil Schemenauer <nas-github@arctrix.com>
+---
+ Include/pyport.h                                   | 14 ++++++++++++++
+ Lib/test/_testcppext.cpp                           |  4 ++++
+ .../2022-06-04-13-15-41.gh-issue-93442.4M4NDb.rst  |  3 +++
+ 3 files changed, 21 insertions(+)
+ create mode 100644 Misc/NEWS.d/next/C API/2022-06-04-13-15-41.gh-issue-93442.4M4NDb.rst
+
+diff --git a/Include/pyport.h b/Include/pyport.h
+index 5a9adf162b..a78e290931 100644
+--- a/Include/pyport.h
++++ b/Include/pyport.h
+@@ -24,9 +24,23 @@
+ //
+ // The type argument must not be a constant type.
+ #ifdef __cplusplus
++#include <cstddef>
+ #  define _Py_STATIC_CAST(type, expr) static_cast<type>(expr)
+ extern "C++" {
+     namespace {
++        template <typename type>
++        inline type _Py_CAST_impl(long int ptr) {
++            return reinterpret_cast<type>(ptr);
++        }
++        template <typename type>
++        inline type _Py_CAST_impl(int ptr) {
++            return reinterpret_cast<type>(ptr);
++        }
++        template <typename type>
++        inline type _Py_CAST_impl(std::nullptr_t) {
++            return static_cast<type>(nullptr);
++        }
++
+         template <typename type, typename expr_type>
+             inline type _Py_CAST_impl(expr_type *expr) {
+                 return reinterpret_cast<type>(expr);
+diff --git a/Lib/test/_testcppext.cpp b/Lib/test/_testcppext.cpp
+index eade7ccdaa..70f434e678 100644
+--- a/Lib/test/_testcppext.cpp
++++ b/Lib/test/_testcppext.cpp
+@@ -74,6 +74,10 @@ test_api_casts(PyObject *Py_UNUSED(module), PyObject *Py_UNUSED(args))
+     Py_INCREF(strong_ref);
+     Py_DECREF(strong_ref);
+ 
++    // gh-93442: Pass 0 as NULL for PyObject*
++    Py_XINCREF(0);
++    Py_XDECREF(0);
++
+     Py_DECREF(obj);
+     Py_RETURN_NONE;
+ }
+diff --git a/Misc/NEWS.d/next/C API/2022-06-04-13-15-41.gh-issue-93442.4M4NDb.rst b/Misc/NEWS.d/next/C API/2022-06-04-13-15-41.gh-issue-93442.4M4NDb.rst
+new file mode 100644
+index 0000000000..f48ed37c81
+--- /dev/null
++++ b/Misc/NEWS.d/next/C API/2022-06-04-13-15-41.gh-issue-93442.4M4NDb.rst	
+@@ -0,0 +1,3 @@
++Add C++ overloads for _Py_CAST_impl() to handle 0/NULL.  This will allow C++
++extensions that pass 0 or NULL to macros using _Py_CAST() to continue to
++compile.

python3.11.spec

@@ -17,7 +17,7 @@ URL: https://www.python.org/
 %global prerel b3
 %global upstream_version %{general_version}%{?prerel}
 Version: %{general_version}%{?prerel:~%{prerel}}
-Release: 3%{?dist}
+Release: 4%{?dist}
 License: Python
 
 
@@ -310,6 +310,19 @@ Patch251: 00251-change-user-install-location.patch
 # Ideally, we should talk to upstream and explain why we don't want this
 Patch328: 00328-pyc-timestamp-invalidation-mode.patch
 
+# 00383 # b4e1d3233b9fbcd9a60370d0f29e65012bb9532d
+# gh-93442: Make C++ version of _Py_CAST work with 0/NULL
+#
+# Add C++ overloads for _Py_CAST_impl() to handle 0/NULL.  This will allow
+# C++ extensions that pass 0 or NULL to macros using _Py_CAST() to
+# continue to compile.  Without this, you get an error like:
+#
+#     invalid ‘static_cast’ from type ‘int’ to type ‘_object*’
+#
+# The modern way to use a NULL value in C++ is to use nullptr.  However,
+# we want to not break extensions that do things the old way.
+Patch383: 00383-gh-93442-make-c-version-of-_py_cast-work-with-0-null.patch
+
 # (New patches go here ^^^)
 #
 # When adding new patches to "python" and "python3" in Fedora, EL, etc.,
@@ -1582,6 +1595,9 @@ CheckPython optimized
 # ======================================================
 
 %changelog
+* Tue Jun 21 2022 Miro Hrončok <mhroncok@redhat.com> - 3.11.0~b3-4
+- Make C++ version of _Py_CAST work with 0/NULL
+
 * Mon Jun 13 2022 Tomáš Hrnčiar <thrnciar@redhat.com> - 3.11.0~b3-3
 - Finish bootstrapping for Python 3.11 mass rebuild