From 14d285bdcd1169ce7af5621a02488b2b3dcbc6b1 Mon Sep 17 00:00:00 2001
From: Honza Bambas <honzab.moz@firemni.cz>
Date: Mon, 1 Aug 2016 04:12:00 +0200
Subject: [PATCH] Bug 1171203 - Fix redirection limit underflow, don't count
 internal redirect to this limit, r=mcmanus

---
 netwerk/protocol/http/HttpBaseChannel.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/netwerk/protocol/http/HttpBaseChannel.cpp b/netwerk/protocol/http/HttpBaseChannel.cpp
index a7c3e9a58fb9..f809889d182a 100644
--- a/netwerk/protocol/http/HttpBaseChannel.cpp
+++ b/netwerk/protocol/http/HttpBaseChannel.cpp
@@ -2973,7 +2973,11 @@ HttpBaseChannel::SetupReplacementChannel(nsIURI       *newURI,
   httpChannel->SetAllowPipelining(mAllowPipelining);
   httpChannel->SetAllowSTS(mAllowSTS);
   // convey the new redirection limit
-  httpChannel->SetRedirectionLimit(mRedirectionLimit - 1);
+  // make sure we don't underflow
+  uint32_t redirectionLimit = mRedirectionLimit
+    ? mRedirectionLimit - 1
+    : 0;
+  httpChannel->SetRedirectionLimit(redirectionLimit);
 
   // convey the Accept header value
   {