From a237a920991f417e9a4567957f4fc7aa5b538270 Mon Sep 17 00:00:00 2001
From: Alexey Botchkov <holyfoot@askmonty.org>
Date: Wed, 13 Sep 2017 00:36:09 +0400
Subject: [PATCH] MDEV-12877 Wrong result from JSON native function.

        Set default charset for temporary paths so UDF call don't crash.
---
 sql/item_jsonfunc.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sql/item_jsonfunc.cc b/sql/item_jsonfunc.cc
index 9295c34aba9..a39b5f3f263 100644
--- a/sql/item_jsonfunc.cc
+++ b/sql/item_jsonfunc.cc
@@ -650,6 +650,7 @@ static int alloc_tmp_paths(THD *thd, uint n_paths,
     if (*tmp_paths == 0)
     {
       MEM_ROOT *root= thd->stmt_arena->mem_root;
+
       *paths= (json_path_with_flags *) alloc_root(root,
           sizeof(json_path_with_flags) * n_paths);
       *tmp_paths= (String *) alloc_root(root, sizeof(String) * n_paths);
@@ -657,6 +658,8 @@ static int alloc_tmp_paths(THD *thd, uint n_paths,
         return 1;
 
       bzero(*tmp_paths, sizeof(String) * n_paths);
+      for (uint c_path=0; c_path < n_paths; c_path++)
+        (*tmp_paths)[c_path].set_charset(&my_charset_utf8_general_ci);
     }
 
     return 0;