From fa44bfb1db94d88e748c51920940bf6f04aac1f8 Mon Sep 17 00:00:00 2001
From: Martin Lagrange <lagrangemartin@gmail.com>
Date: Mon, 22 Jun 2015 16:07:45 +0200
Subject: [PATCH] COUCHDB-2722
 https://issues.apache.org/jira/browse/COUCHDB-2722

---
 src/couch_httpd_rewrite.erl | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/couch_httpd_rewrite.erl b/src/couch_httpd_rewrite.erl
index e2a24218..1f68578f 100644
--- a/src/couch_httpd_rewrite.erl
+++ b/src/couch_httpd_rewrite.erl
@@ -271,8 +271,11 @@ replace_var(Value, _Bindings, _Formats) when is_binary(Value) ->
     Value;
 replace_var(Value, Bindings, Formats) when is_list(Value) ->
     lists:reverse(lists:foldl(fun
-                (<<":", Var/binary>>=Value1, Acc) ->
-                    [get_var(Var, Bindings, Value1, Formats)|Acc];
+                (<<":", Var/binary>>, Acc) ->
+                    case get_var(Var, Bindings, undefined, Formats) of 
+                         undefined -> [''|Acc] ;
+                         DefinedValue -> [DefinedValue|Acc]
+                    end;
                 (Value1, Acc) ->
                     [Value1|Acc]
             end, [], Value));