From b18165e704640ab7c4e2798529e0829bfbd29c3c Mon Sep 17 00:00:00 2001
From: Marshall Clow <mclow@qualcomm.com>
Date: Thu, 7 Feb 2013 18:48:09 +0000
Subject: [PATCH] Belt and suspenders when calling sysconf

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@174642 91177308-0d34-0410-b5e6-96231b3b80d8
---
 src/thread.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/thread.cpp b/src/thread.cpp
index 184d81e6..447eca7b 100644
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -69,7 +69,9 @@ thread::hardware_concurrency() _NOEXCEPT
     long result = sysconf(_SC_NPROCESSORS_ONLN);
     // sysconf returns -1 if the name is invalid, the option does not exist or
     // does not have a definite limit.
-    if (result == -1)
+    // if sysconf returns some other negative number, we have no idea
+    // what is going on. Default to something safe.
+    if (result < 0)
         return 0;
     return static_cast<unsigned>(result);
 #else  // defined(CTL_HW) && defined(HW_NCPU)