Assertion `(length % 4) == 0' failed in my_lengthsp_utf32 on ALTER TABLE, SELECT and INSERT

USE test;

SET COLLATION_CONNECTION=utf32_myanmar_ci, CHARACTER_SET_CLIENT=binary;

CREATE TABLE t (a CHAR(1));

ALTER TABLE t CHANGE a a ENUM('a','a') CHARACTER SET utf32;

mysqld: /test/10.5_dbg/strings/ctype-ucs2.c:2197: my_lengthsp_utf32: Assertion `(length % 4) == 0' failed.

Core was generated by `/test/MD140720-mariadb-10.5.5-linux-x86_64-dbg/bin/mysqld --no-defaults --core-'.

Program terminated with signal SIGABRT, Aborted.

#0  __pthread_kill (threadid=<optimized out>, signo=signo@entry=6)

    at ../sysdeps/unix/sysv/linux/pthread_kill.c:57

[Current thread is 1 (Thread 0x1482c7848700 (LWP 1820126))]

(gdb) bt

#0  __pthread_kill (threadid=<optimized out>, signo=signo@entry=6) at ../sysdeps/unix/sysv/linux/pthread_kill.c:57

#1  0x000055b87dda34d7 in my_write_core (sig=sig@entry=6) at /test/10.5_dbg/mysys/stacktrace.c:518

#2  0x000055b87d55d9ba in handle_fatal_signal (sig=6) at /test/10.5_dbg/sql/signal_handler.cc:330

#3  <signal handler called>

#4  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51

#5  0x00001482c5ade8b1 in __GI_abort () at abort.c:79

#6  0x00001482c5ace42a in __assert_fail_base (fmt=0x1482c5c55a38 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=assertion@entry=0x55b87e488872 "(length % 4) == 0", file=file@entry=0x55b87e488800 "/test/10.5_dbg/strings/ctype-ucs2.c", line=line@entry=2197, function=function@entry=0x55b87e488db0 <__PRETTY_FUNCTION__.15905> "my_lengthsp_utf32") at assert.c:92

#7  0x00001482c5ace4a2 in __GI___assert_fail (assertion=assertion@entry=0x55b87e488872 "(length % 4) == 0", file=file@entry=0x55b87e488800 "/test/10.5_dbg/strings/ctype-ucs2.c", line=line@entry=2197, function=function@entry=0x55b87e488db0 <__PRETTY_FUNCTION__.15905> "my_lengthsp_utf32") at assert.c:101

#8  0x000055b87ddddc15 in my_lengthsp_utf32 (cs=<optimized out>, ptr=<optimized out>, length=<optimized out>) at /test/10.5_dbg/strings/ctype-ucs2.c:2197

#9  0x000055b87d53e9a8 in charset_info_st::lengthsp (length=<optimized out>, str=0x1482a34749a8 "a", this=<optimized out>) at /test/10.5_dbg/include/m_ctype.h:622

#10 Column_definition::create_interval_from_interval_list (this=this@entry=0x1482a3474a58, mem_root=mem_root@entry=0x1482a341ab50, reuse_interval_list_values=reuse_interval_list_values@entry=true) at /test/10.5_dbg/sql/field.cc:10060

#11 0x000055b87d53ed61 in Column_definition::prepare_interval_field (this=this@entry=0x1482a3474a58, mem_root=mem_root@entry=0x1482a341ab50, reuse_interval_list_values=reuse_interval_list_values@entry=true) at /test/10.5_dbg/sql/field.cc:10117

#12 0x000055b87d3778f2 in Column_definition::prepare_stage1_typelib (this=0x1482a3474a58, thd=0x1482a3415088, mem_root=0x1482a341ab50, file=0x1482a3474d38, table_flags=<optimized out>) at /test/10.5_dbg/sql/sql_table.cc:3232

#13 0x000055b87d484cb8 in Type_handler_typelib::Column_definition_prepare_stage1 (this=<optimized out>, thd=<optimized out>, mem_root=<optimized out>, def=<optimized out>, file=<optimized out>, table_flags=<optimized out>) at /test/10.5_dbg/sql/sql_type.cc:2991

#14 0x000055b87d3775ab in Column_definition::prepare_stage1 (this=this@entry=0x1482a3474a58, thd=thd@entry=0x1482a3415088, mem_root=<optimized out>, file=file@entry=0x1482a3474d38, table_flags=<optimized out>) at /test/10.5_dbg/sql/sql_table.cc:3295

#15 0x000055b87d37e9d8 in mysql_prepare_create_table (thd=thd@entry=0x1482a3415088, create_info=create_info@entry=0x1482c7846220, alter_info=alter_info@entry=0x1482c7846150, db_options=db_options@entry=0x1482c7843828, file=file@entry=0x1482a3474d38, key_info_buffer=key_info_buffer@entry=0x1482c78441d0, key_count=0x1482c78441c8, create_table_mode=-2) at /test/10.5_dbg/sql/sql_table.cc:3635

#16 0x000055b87d382500 in mysql_create_frm_image (thd=thd@entry=0x1482a3415088, db=@0x1482c7845640: {str = 0x1482a3474898 "test", length = 4}, table_name=@0x1482c7845650: {str = 0x1482a3474190 "t", length = 1}, create_info=create_info@entry=0x1482c7846220, alter_info=alter_info@entry=0x1482c7846150, create_table_mode=create_table_mode@entry=-2, key_info=0x1482c78441d0, key_count=0x1482c78441c8, frm=0x1482c78441e0) at /test/10.5_dbg/sql/sql_table.cc:5015

#17 0x000055b87d382f3d in create_table_impl (thd=thd@entry=0x1482a3415088, orig_db=@0x1482c7845640: {str = 0x1482a3474898 "test", length = 4}, orig_table_name=@0x1482c7845650: {str = 0x1482a3474190 "t", length = 1}, db=@0x1482c7845670: {str = 0x1482a3474898 "test", length = 4}, table_name=@0x1482c78456a0: {str = 0x1482c78459da "#sql-alter-1bc5bd-4", length = 19}, path=path@entry=0x1482c7845e9d "./test/#sql-alter-1bc5bd-4", options={m_options = DDL_options_st::OPT_NONE}, create_info=0x1482c7846220, alter_info=0x1482c7846150, create_table_mode=-2, is_trans=0x0, key_info=0x1482c78441d0, key_count=0x1482c78441c8, frm=0x1482c78441e0) at /test/10.5_dbg/sql/sql_table.cc:5271

#18 0x000055b87d38985b in mysql_alter_table (thd=thd@entry=0x1482a3415088, new_db=new_db@entry=0x1482a3419948, new_name=new_name@entry=0x1482a3419d50, create_info=create_info@entry=0x1482c7846220, table_list=<optimized out>, table_list@entry=0x1482a34741c8, alter_info=alter_info@entry=0x1482c7846150, order_num=0, order=0x0, ignore=false, if_exists=false) at /test/10.5_dbg/sql/sql_table.cc:10435

#19 0x000055b87d40da6a in Sql_cmd_alter_table::execute (this=<optimized out>, thd=0x1482a3415088) at /test/10.5_dbg/sql/sql_alter.cc:532

#20 0x000055b87d2b6e4a in mysql_execute_command (thd=thd@entry=0x1482a3415088) at /test/10.5_dbg/sql/sql_parse.cc:5951

#21 0x000055b87d2be752 in mysql_parse (thd=thd@entry=0x1482a3415088, rawbuf=<optimized out>, length=<optimized out>, parser_state=parser_state@entry=0x1482c7847350, is_com_multi=is_com_multi@entry=false, is_next_command=is_next_command@entry=false) at /test/10.5_dbg/sql/sql_parse.cc:7993

#22 0x000055b87d2ab204 in dispatch_command (command=command@entry=COM_QUERY, thd=thd@entry=0x1482a3415088, packet=packet@entry=0x1482a3467089 "ALTER TABLE t CHANGE a a ENUM('a','a') CHARACTER SET utf32", packet_length=packet_length@entry=58, is_com_multi=is_com_multi@entry=false, is_next_command=is_next_command@entry=false) at /test/10.5_dbg/sql/sql_parse.cc:1866

#23 0x000055b87d2a99de in do_command (thd=0x1482a3415088) at /test/10.5_dbg/sql/sql_parse.cc:1347

#24 0x000055b87d405c3b in do_handle_one_connection (connect=<optimized out>, connect@entry=0x1482a68c7808, put_in_cache=put_in_cache@entry=true) at /test/10.5_dbg/sql/sql_connect.cc:1411

#25 0x000055b87d406357 in handle_one_connection (arg=arg@entry=0x1482a68c7808) at /test/10.5_dbg/sql/sql_connect.cc:1313

#26 0x000055b87d869ca8 in pfs_spawn_thread (arg=0x1482c4446508) at /test/10.5_dbg/storage/perfschema/pfs.cc:2201

#27 0x00001482c67c16db in start_thread (arg=0x1482c7848700) at pthread_create.c:463

#28 0x00001482c5bbfa3f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95