From 70e13a9ca895db7f4f19ddc3bd0f016320225058 Mon Sep 17 00:00:00 2001
From: Marshall Clow <mclow.lists@gmail.com>
Date: Mon, 23 Mar 2015 20:07:17 +0000
Subject: [PATCH] Fix incorrect error handling of call to mbrtowc. This is
 PR#13759. Leaving the bug open because (1) I'm not sure that we're correct
 here, only better than before, and (2) no tests

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@233012 91177308-0d34-0410-b5e6-96231b3b80d8
---
 src/locale.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/locale.cpp b/src/locale.cpp
index 54a24e68c..2842bfccb 100644
--- a/src/locale.cpp
+++ b/src/locale.cpp
@@ -1657,7 +1657,7 @@ codecvt<wchar_t, char, mbstate_t>::do_in(state_type& st,
             frm_nxt = frm;
             return frm_nxt == frm_end ? ok : partial;
         }
-        if (n == 0)
+        if (n == (size_t)-1)
             return error;
         to_nxt += n;
         if (to_nxt == to_end)