From 8711adb7863b10fd868cc2b1c84c3416e715b539 Mon Sep 17 00:00:00 2001
From: Sergei Golubchik <serg@mariadb.org>
Date: Wed, 30 Jun 2021 01:00:50 +0200
Subject: [PATCH] fix JSON_ARRAYAGG not to over-quote json in joins

use metadata (in particular is_json() property) of the original
argument item, even if the actual argument was later replaced
with an Item_temptable_field
---
 mysql-test/main/func_json.result | 6 +++---
 sql/item_jsonfunc.cc             | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/mysql-test/main/func_json.result b/mysql-test/main/func_json.result
index 0c242a886b7..a889cb228b7 100644
--- a/mysql-test/main/func_json.result
+++ b/mysql-test/main/func_json.result
@@ -1376,9 +1376,9 @@ SELECT t1.id, JSON_ARRAYAGG(JSON_OBJECT('id',t2.id)) as materials
 from t1 LEFT JOIN t2 on t1.id = t2.owner_id
 GROUP BY t1.id ORDER BY id;
 id	materials
-1	["{\"id\": 1}","{\"id\": 2}"]
-2	["{\"id\": 3}"]
-3	["{\"id\": 4}"]
+1	[{"id": 1},{"id": 2}]
+2	[{"id": 3}]
+3	[{"id": 4}]
 DROP TABLE t1;
 DROP TABLE t2;
 #
diff --git a/sql/item_jsonfunc.cc b/sql/item_jsonfunc.cc
index 4b63b119a83..60c0e4cc2fe 100644
--- a/sql/item_jsonfunc.cc
+++ b/sql/item_jsonfunc.cc
@@ -3723,12 +3723,12 @@ String *Item_func_json_arrayagg::get_str_from_item(Item *i, String *tmp)
 }
 
 
-String *Item_func_json_arrayagg::get_str_from_field(Item *i,Field *f,
+String *Item_func_json_arrayagg::get_str_from_field(Item *, Field *f,
     String *tmp, const uchar *key, size_t offset)
 {
   m_tmp_json.length(0);
 
-  if (append_json_value_from_field(&m_tmp_json, i, f, key, offset, tmp))
+  if (append_json_value_from_field(&m_tmp_json, *orig_args, f, key, offset, tmp))
     return NULL;
 
   return &m_tmp_json;