SIGSEGV in Item_func_json_extract::read_json when using JSON_EXTRACT<=>VARCHAR

I noticed a crash on every version of MariaDB when running something similar to the following:

create table tst(val json);

insert into tst values('{}');

select t.val<=>json_extract('[]','$') from tst t;

Though it can be reproduced also by running just this

select '[]'<=>json_extract('[]','$')

The problem being the comparison of JSON and VARCHAR with the <=> operator.

I suppose the problem is that even though MariaDB accepts the token json as data type, it desugars to longtext, but internally, there is still a distinct type for json data.