From 37ee73cda9c99cf069f6de7a9ef1b850e204c9c7 Mon Sep 17 00:00:00 2001
From: Saleem Abdulrasool <compnerd@compnerd.org>
Date: Tue, 14 Jul 2020 20:01:12 -0700
Subject: [PATCH] runtime: correct the `asprintf` shim for Windows

Ensure that the string that is formed from the `asprintf` call is
null-terminated.  The `_vsnprintf` call will not null-terminate the
string if the length is not sufficient.
---
 stdlib/public/runtime/ReflectionMirror.mm | 1 +
 1 file changed, 1 insertion(+)

diff --git a/stdlib/public/runtime/ReflectionMirror.mm b/stdlib/public/runtime/ReflectionMirror.mm
index 74a644912e1..b24737360dc 100644
--- a/stdlib/public/runtime/ReflectionMirror.mm
+++ b/stdlib/public/runtime/ReflectionMirror.mm
@@ -56,6 +56,7 @@ int asprintf(char **strp, const char *fmt, ...) {
     return -1;
 
   length = _vsnprintf(*strp, length, fmt, argp1);
+  (*strp)[length] = '\0';
 
   va_end(argp0);
   va_end(argp1);