JSON functions are broken

Build tested: 1.4.4-1, 1.5.2-1 (community edition, b33685)

The following json functions return a "got bad column" error.

JSON_ARRAY_APPEND.sql
JSON_ARRAY_INSERT.sql
JSON_COMPACT.sql
JSON_CONTAINS_PATH.sql
JSON_CONTAINS.sql
JSON_DEPTH.sql
JSON_DETAILED.sql
JSON_EXISTS.sql
JSON_EXTRACT.sql
JSON_INSERT.sql
JSON_KEYS.sql
JSON_LENGTH.sql
JSON_LOOSE.sql
JSON_MERGE.sql
JSON_QUERY.sql
JSON_QUOTE.sql
JSON_REMOVE.sql
JSON_REPLACE.sql
JSON_SEARCH.sql
JSON_SET.sql
JSON_TYPE.sql
JSON_UNQUOTE.sql
JSON_VALID.sql
JSON_VALUE.sql

For example:

[centos7:root~]# cat -n /data/qa/autopilot/features/json/sql/JSON_EXISTS.sql
1 # ---------------------------------------------------------------------- #
2 # The string is already a JSON string so we can insert it into the table
3 # ---------------------------------------------------------------------- #
4 TRUNCATE TABLE jsontest;
5 SET @json = '

{"key1":"xxxx", "key2":[1, 2, 3]}

';
6 SELECT @json;
7 INSERT INTO jsontest VALUES (1, @json, @json);
8 #
9 SELECT JSON_EXISTS(@json, "$.key2");
10 SELECT JSON_EXISTS(@json, "$.key3");
11 SELECT JSON_EXISTS(@json, "$.key2[1]");
12 SELECT JSON_EXISTS(@json, "$.key2[10]");
13 #
14 SELECT * FROM jsontest;
15 SELECT cVarchar, JSON_EXISTS(cVarchar, "$.key2"), cText, JSON_EXISTS(cText, "$.key2") from jsontest;
16 SELECT cVarchar, JSON_EXISTS(cVarchar, "$.key3"), cText, JSON_EXISTS(cText, "$.key3") from jsontest;
17 SELECT cVarchar, JSON_EXISTS(cVarchar, "$.key2[1]"), cText, JSON_EXISTS(cText, "$.key2[1]") from jsontest;
18 SELECT cVarchar, JSON_EXISTS(cVarchar, "$.key2[10]"), cText, JSON_EXISTS(cText, "$.key2[10]") from jsontest;
19 #
20 TRUNCATE TABLE jsontest;

[centos7:root~]# cat JSON_EXISTS.sql.tst.log
ERROR 1815 (HY000) at line 15: Internal error: Error while fetching from ExeMgr: Row::isNullValue(): got bad column type (738197656). Width=738398448

ERROR 1815 (HY000) at line 16: Internal error: Unknown error
ERROR 1815 (HY000) at line 17: Internal error: Error while fetching from ExeMgr: Row::isNullValue(): got bad column type (738393232). Width=738409744

ERROR 1815 (HY000) at line 18: Internal error: Unknown error
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