Server crashes when adding records to table after setting redirect_url with empty variable

SET GLOBAL redirect_url=@empty_value;

CREATE TABLE t (c1 INT) ENGINE=INNODB;

INSERT INTO t VALUES (1),(1);

Core was generated by `/test/mtest/MD180923-mariadb-11.3.0-linux-x86_64-opt/bin/mariadbd --no-defaults'.

Program terminated with signal SIGSEGV, Segmentation fault.

#0  __strlen_avx2 () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:65

[Current thread is 1 (Thread 0x14aef61f0700 (LWP 210291))]

(gdb) bt

#0  __strlen_avx2 () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:65

#1  0x000055d21b311921 in my_strdup (key=0, from=0x0, my_flags=my_flags@entry=65552) at /test/mtest/11.3_opt/mysys/my_malloc.c:236

#2  0x000055d21ac1a0a8 in plugin_thdvar_init (thd=thd@entry=0x14ae94002f28) at /test/mtest/11.3_opt/sql/sql_plugin.cc:3271

#3  0x000055d21aba582b in THD::init (this=this@entry=0x14ae94002f28) at /test/mtest/11.3_opt/sql/sql_class.cc:1229

#4  0x000055d21abab87c in THD::THD (this=0x14ae94002f28, id=<optimized out>, is_wsrep_applier=<optimized out>) at /test/mtest/11.3_opt/sql/sql_class.cc:851

#5  0x000055d21ababd02 in create_background_thd () at /test/mtest/11.3_opt/sql/sql_list.h:680

#6  0x000055d21b0edfa4 in innobase_create_background_thd (name=name@entry=0x55d21b69e430 "InnoDB statistics") at /test/mtest/11.3_opt/storage/innobase/handler/ha_innodb.cc:1713

#7  0x000055d21b25634c in dict_stats_func () at /test/mtest/11.3_opt/storage/innobase/dict/dict0stats_bg.cc:374

#8  0x000055d21b2b336d in tpool::thread_pool_generic::timer_generic::run (this=0x55d21d0000e0) at /test/mtest/11.3_opt/tpool/tpool_generic.cc:343

#9  tpool::thread_pool_generic::timer_generic::execute (arg=0x55d21d0000e0) at /test/mtest/11.3_opt/tpool/tpool_generic.cc:363

#10 0x000055d21b2b400a in tpool::task::execute (this=0x55d21d000120) at /test/mtest/11.3_opt/tpool/task.cc:37

#11 tpool::task::execute (this=0x55d21d000120) at /test/mtest/11.3_opt/tpool/task.cc:27

#12 0x000055d21b2b1a97 in tpool::thread_pool_generic::worker_main (this=0x55d21cf67330, thread_var=0x55d21cf68460) at /test/mtest/11.3_opt/tpool/tpool_generic.cc:580

#13 0x000014af31279de4 in ?? () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6

#14 0x000014af31393609 in start_thread (arg=<optimized out>) at pthread_create.c:477

#15 0x000014af30f7f133 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95