From fcc532470aa56e7a2e345f7f2396774787feb2ce Mon Sep 17 00:00:00 2001
From: KWSys Upstream <kwrobot@kitware.com>
Date: Wed, 24 Aug 2016 10:53:55 -0400
Subject: [PATCH] KWSys 2016-08-24 (8e643b9b)

Code extracted from:

    http://public.kitware.com/KWSys.git

at commit 8e643b9b5f24d4cac68d59b1e2be9d161fb75974 (master).

Upstream Shortlog
-----------------

Brad King (1):
      8e643b9b SystemTools: Fix crash in GetShortPath
---
 SystemTools.cxx | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/SystemTools.cxx b/SystemTools.cxx
index eb2bec65f..1a73b164b 100644
--- a/SystemTools.cxx
+++ b/SystemTools.cxx
@@ -4725,8 +4725,11 @@ bool SystemTools::GetShortPath(const std::string& path, std::string& shortPath)
   std::wstring wtempPath = Encoding::ToWide(tempPath);
   DWORD ret = GetShortPathNameW(wtempPath.c_str(), NULL, 0);
   std::vector<wchar_t> buffer(ret);
-  ret = GetShortPathNameW(wtempPath.c_str(),
-                          &buffer[0], static_cast<DWORD>(buffer.size()));
+  if (ret != 0)
+    {
+    ret = GetShortPathNameW(wtempPath.c_str(),
+                            &buffer[0], static_cast<DWORD>(buffer.size()));
+    }
 
   if (ret == 0)
     {