BUG #13934: wrong result of split_part with char value

The following bug has been logged on the website:

Bug reference: 13934
Logged by: Dominik Kosiorek
Email address: dominik(dot)kosiorek(at)infobright(dot)com
PostgreSQL version: 9.2.2
Operating system: Ubuntu 14
Description:

create table string1postgres(
a1 int,
a2 char(65),
a3pattern char(15),
a4field int
)
insert into string1postgres values(72,'abcd defg poir abcde m ert g d c v b
gthb',' ',1);

select split_part(a2,a3pattern,a4field) from string1postgres;

-------------------
the result of split part is:
-------------------
abcd defg poir abcde m ert g d c v b gthb

-------------------
instead of:
-------------------
abcd

-------------------
This defect is only with char type. On varchar result is correct.