From e77ca2c471f3d581e2e029d22343fc67ccce7a14 Mon Sep 17 00:00:00 2001
From: Jordan Harband <ljharb@gmail.com>
Date: Sun, 21 Mar 2021 20:00:46 -0700
Subject: [PATCH] [Fix] `stringify`: avoid exception on repeated object values

Fixes #402
---
 lib/stringify.js  |  3 ++-
 test/stringify.js | 22 ++++++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/lib/stringify.js b/lib/stringify.js
index ab7a37e2..b8cee4bc 100644
--- a/lib/stringify.js
+++ b/lib/stringify.js
@@ -137,6 +137,7 @@ var stringify = function stringify(
             : prefix + (allowDots ? '.' + key : '[' + key + ']');
 
         sideChannel.set(object, true);
+        var valueSideChannel = getSideChannel();
         pushToArray(values, stringify(
             value,
             keyPrefix,
@@ -152,7 +153,7 @@ var stringify = function stringify(
             formatter,
             encodeValuesOnly,
             charset,
-            sideChannel
+            valueSideChannel
         ));
     }
 
diff --git a/test/stringify.js b/test/stringify.js
index b2b3f4b5..931ac0dd 100644
--- a/test/stringify.js
+++ b/test/stringify.js
@@ -465,6 +465,28 @@ test('stringify()', function (t) {
         st.end();
     });
 
+    t.test('non-circular duplicated references can still work', function (st) {
+        var hourOfDay = {
+            'function': 'hour_of_day'
+        };
+
+        var p1 = {
+            'function': 'gte',
+            arguments: [hourOfDay, 0]
+        };
+        var p2 = {
+            'function': 'lte',
+            arguments: [hourOfDay, 23]
+        };
+
+        st.equal(
+            qs.stringify({ filters: { $and: [p1, p2] } }, { encodeValuesOnly: true }),
+            'filters[$and][0][function]=gte&filters[$and][0][arguments][0][function]=hour_of_day&filters[$and][0][arguments][1]=0&filters[$and][1][function]=lte&filters[$and][1][arguments][0][function]=hour_of_day&filters[$and][1][arguments][1]=23'
+        );
+
+        st.end();
+    });
+
     t.test('selects properties when filter=array', function (st) {
         st.equal(qs.stringify({ a: 'b' }, { filter: ['a'] }), 'a=b');
         st.equal(qs.stringify({ a: 1 }, { filter: [] }), '');