Server crashes at gsignal

SELECT JSON_SCHEMA_VALID ( '{"properties": "a_string": {"pattern": "^[5-9]$"}}}' , '{"a_string": "8"}' ) x , x ;

#0 0x72bcd261000b (gsignal+0xcb)

#1 0x72bcd25ef859 (abort+0x12b)

#2 0x72bcd265a266 (__fsetlocking+0x426)

#3 0x72bcd26622fc (pthread_attr_setschedparam+0x54c)

#4 0x72bcd2663b2c (pthread_attr_setschedparam+0x1d7c)

#5 0x620759ce682d (delete_dynamic+0x4d)

#6 0x620759cee84c (my_hash_free+0xdc)

#7 0x62075924ab33 (_ZN22Json_schema_propertiesD0Ev+0x43)

#8 0x62075922d816 (_ZN27Item_func_json_schema_valid7cleanupEv+0x66)

#9 0x620758eb1a90 (_ZN3THD19cleanup_after_queryEv+0x3b0)

#10 0x620758f4c9d1 (_Z16dispatch_command19enum_server_commandP3THDPcjb+0x16b1)

#11 0x620758f50cd1 (_Z10do_commandP3THDb+0x4b1)

#12 0x620759186b74 (_Z24do_handle_one_connectionP7CONNECTb+0x2a4)

#13 0x6207591867a3 (handle_one_connection+0xd3)

#14 0x62075984f0b4 (pfs_spawn_thread+0x104)

#15 0x72bcd29ca609 (start_thread+0xd9)

#16 0x72bcd26ec353 (clone+0x43)