[Python-checkins] Fix MSVC warning in frameobject.c (GH-20590)

[Ammar Askar]

https://github.com/python/cpython/commit/6e23a9c82b7fd2366003b9191cd93a9683b9d80c
commit: 6e23a9c82b7fd2366003b9191cd93a9683b9d80c
branch: master
author: Ammar Askar <ammar at ammaraskar.com>
committer: GitHub <noreply at github.com>
date: 2020-06-04T06:19:23+01:00
summary:

Fix MSVC warning in frameobject.c (GH-20590)

files:
M Objects/frameobject.c

diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index af32276c98b24..b6d073bd456d0 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -397,7 +397,9 @@ frame_setlineno(PyFrameObject *f, PyObject* p_new_lineno, void *Py_UNUSED(ignore
         return -1;
     }
 
-    int len = PyBytes_GET_SIZE(f->f_code->co_code)/sizeof(_Py_CODEUNIT);
+    int len = Py_SAFE_DOWNCAST(
+        PyBytes_GET_SIZE(f->f_code->co_code)/sizeof(_Py_CODEUNIT),
+        Py_ssize_t, int);
     int *lines = marklines(f->f_code, len);
     if (lines == NULL) {
         return -1;