BUG #16144: Segmentation fault on dict_int extension

The following bug has been logged on the website:

Bug reference: 16144
Logged by: cili
Email address: cilizili(at)protonmail(dot)com
PostgreSQL version: 12.1
Operating system: CentOS 7.4
Description:

The dict_int extension is an example of an add-on dictionary template for
full-text search. The 'intdict' is a built-in dictionary. If we set MAXLEN
parameter with negative value for the dictionary, ts_lexize function causes
a segmentation fault. The negative limit for MAXLEN which causes
segmentation fault is environment dependent.

# initdb
# pg_ctl -D /var/lib/pgsql/data -l logfile start
# psql

postgres=# CREATE EXTENSION dict_int;
CREATE EXTENSION
postgres=# ALTER TEXT SEARCH DICTIONARY intdict (MAXLEN = -214783648);
ALTER TEXT SEARCH DICTIONARY
postgres=# select ts_lexize('intdict', '12345678');
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!>
!>\q

# cat /var/lib/pgsql/data/pg_log/postgresql-Mon.log
LOG: database system was shut down at 2019-12-02 12:05:17 UTC
LOG: database system is ready to accept connections
LOG: autovacuum launcher started
LOG: server process (PID 5288) was terminated by signal 11: Segmentation
fault
DETAIL: Failed process was running: select ts_lexize('intdict',
'12345678');
LOG: terminating any other active server processes
WARNING: terminating connection because of crash of another server
process
DETAIL: The postmaster has commanded this server process to roll back the
current transaction and exit, because another server process exited
abnormally and possibly corrupted shared memory.
HINT: In a moment you should be able to reconnect to the database and
repeat your command.
LOG: all server processes terminated; reinitializing
FATAL: the database system is in recovery mode
LOG: database system was interrupted; last known up at 2019-12-02 12:05:24
UTC
LOG: database system was not properly shut down; automatic recovery in
progress
LOG: redo starts at 0/180D7F8
LOG: record with zero length at 0/1822720
LOG: redo done at 0/18226F0
LOG: last completed transaction was at log time 2019-12-02
12:05:42.199372+00
LOG: database system is ready to accept connections
LOG: autovacuum launcher started