MDEV-11452 JSON_CONTAINS accepts wrong number of arguments.

        Create_func_json_contains::create_native fixed.

mysql-test/r/func_json.result

@@ -76,6 +76,8 @@ json_contains('"you"', '"you"')
 select json_contains('"youth"', '"you"');
 json_contains('"youth"', '"you"')
 0
+select json_contains('[1]', '[1]', '$', '$[0]');
+ERROR 42000: Incorrect parameter count in the call to native function 'json_contains'
 select json_contains_path('{"key1":1, "key2":[2,3]}', "oNE", "$.key2[1]");
 json_contains_path('{"key1":1, "key2":[2,3]}', "oNE", "$.key2[1]")
 1

mysql-test/t/func_json.test

@@ -30,6 +30,8 @@ SELECT JSON_ARRAY_INSERT('["a", {"b": [1, 2]}, [3, 4]]', '$[4]', 'x');
 select json_contains('{"k1":123, "k2":345}', '123', '$.k1');
 select json_contains('"you"', '"you"');
 select json_contains('"youth"', '"you"');
+--error ER_WRONG_PARAMCOUNT_TO_NATIVE_FCT
+select json_contains('[1]', '[1]', '$', '$[0]');
 
 select json_contains_path('{"key1":1, "key2":[2,3]}', "oNE", "$.key2[1]");
 select json_contains_path('{"key1":1, "key2":[2,3]}', "oNE", "$.key2[10]");

sql/item_create.cc

@@ -5218,13 +5218,13 @@ Create_func_json_contains::create_native(THD *thd, LEX_STRING name,
   if (item_list != NULL)
     arg_count= item_list->elements;
 
-  if (arg_count < 2 /* json_doc, val, [path]...*/)
+  if (arg_count == 2 || arg_count == 3/* json_doc, val, [path] */)
   {
-    my_error(ER_WRONG_PARAMCOUNT_TO_NATIVE_FCT, MYF(0), name.str);
+    func= new (thd->mem_root) Item_func_json_contains(thd, *item_list);
   }
   else
   {
-    func= new (thd->mem_root) Item_func_json_contains(thd, *item_list);
+    my_error(ER_WRONG_PARAMCOUNT_TO_NATIVE_FCT, MYF(0), name.str);
   }
 
   return func;