From 6db3552e69843d1febe9da0fdbffba49359b3c48 Mon Sep 17 00:00:00 2001
From: Honza Bambas <honzab.moz@firemni.cz>
Date: Sat, 18 Feb 2017 07:31:00 -0500
Subject: [PATCH] Bug 1340803 - Make nsMIMEInfoWin::GetPossibleLocalHandlers
 check fileExt is non-empty before checking its first char. r=jimm

--HG--
extra : rebase_source : a3d43e53ddd9f0b5d084434bad88ac0463f8686f
---
 uriloader/exthandler/win/nsMIMEInfoWin.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/uriloader/exthandler/win/nsMIMEInfoWin.cpp b/uriloader/exthandler/win/nsMIMEInfoWin.cpp
index 2c7171c87703..956cbda427a6 100644
--- a/uriloader/exthandler/win/nsMIMEInfoWin.cpp
+++ b/uriloader/exthandler/win/nsMIMEInfoWin.cpp
@@ -612,8 +612,9 @@ nsMIMEInfoWin::GetPossibleLocalHandlers(nsIArray **_retval)
   }
 
   nsAutoString fileExtToUse;
-  if (fileExt.First() != '.')
+  if (!fileExt.IsEmpty() && fileExt.First() != '.') {
     fileExtToUse = char16_t('.');
+  }
   fileExtToUse.Append(NS_ConvertUTF8toUTF16(fileExt));
 
   // Note, the order in which these occur has an effect on the