commit b03623227ed1264e3cac4e6bb4878d96b91aa484
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Thu Sep 07 11:35:03 2017 -0700
committer Benjamin Peterson <benjamin@python.org> Thu Sep 07 11:35:03 2017 -0700
tree 019511e476f77bf6ed4e2cbfd9c8280ff89d9e96
parent b0d0217c0e4c1512a06ef306928b2fd8f82d046e

[3.6] fixes bpo-31373: fix undefined floating-point demotions (GH-3396) (#3424)

(cherry picked from commit a853a8ba7850381d49b284295dd6f0dc491dbe44)

Python/getargs.c

diff --git a/Python/getargs.c b/Python/getargs.c
index 616c6eb..8fb19f3 100644
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -4,6 +4,7 @@
 #include "Python.h"
 
 #include <ctype.h>
+#include <float.h>
 
 
 #ifdef __cplusplus
@@ -810,6 +811,10 @@
         double dval = PyFloat_AsDouble(arg);
         if (PyErr_Occurred())
             RETURN_ERR_OCCURRED;
+        else if (dval > FLT_MAX)
+            *p = (float)INFINITY;
+        else if (dval < -FLT_MAX)
+            *p = (float)-INFINITY;
         else
             *p = (float) dval;
         break;