From ef66f31ce21cd759cc0c618c5c42ba6da0a06834 Mon Sep 17 00:00:00 2001
From: Steve Dower <steve.dower@python.org>
Date: Mon, 9 Sep 2019 06:24:15 -0700
Subject: [PATCH] bpo-32587: Fixes unsafe downcast in PC/winreg.c (GH-15766)

---
 PC/winreg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/PC/winreg.c b/PC/winreg.c
index 37bc2c72dcd..72a7c380bee 100644
--- a/PC/winreg.c
+++ b/PC/winreg.c
@@ -772,7 +772,7 @@ Reg2Py(BYTE *retDataBuf, DWORD retDataSize, DWORD typ)
                         return NULL;
                     }
                     PyList_SET_ITEM(obData, index, uni);
-                    len -= slen + 1;
+                    len -= Py_SAFE_DOWNCAST(slen + 1, size_t, int);
                 }
                 PyMem_Free(str);