From 2245638c1ebeb2d550ed480274c332ad395c94d1 Mon Sep 17 00:00:00 2001
From: Dave Longley <dlongley@digitalbazaar.com>
Date: Tue, 8 Jul 2014 12:59:37 -0400
Subject: [PATCH] Preserve existing @reverse map when merging properties.

---
 jsonld.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/jsonld.php b/jsonld.php
index 53c9b94..7c14c83 100644
--- a/jsonld.php
+++ b/jsonld.php
@@ -2435,7 +2435,11 @@ class JsonLdProcessor {
       if(property_exists($active_ctx->mappings, $key) &&
         $active_ctx->mappings->{$key} &&
         $active_ctx->mappings->{$key}->reverse) {
-        $reverse_map = $rval->{'@reverse'} = new stdClass();
+        if(property_exists($rval, '@reverse')) {
+          $reverse_map = $rval->{'@reverse'};
+        } else {
+          $reverse_map = $rval->{'@reverse'} = new stdClass();
+        }
         $expanded_value = self::arrayify($expanded_value);
         foreach($expanded_value as $item) {
           if(self::_isValue($item) || self::_isList($item)) {