`set_var_collation_client::update()` Segfault in Buildbot `amd64-msan-clang-20`

Thread pointer: 0x72b0000ee018

stack_bottom = 0x7ffe13c9f000 thread_stack 0x49000

/home/buildbot/amd64-msan-clang-20/build/sql/mariadbd(___interceptor_backtrace+0xd2)[0x5567099ec562]

/home/buildbot/amd64-msan-clang-20/build/sql/mariadbd(my_print_stacktrace+0x6a)[0x55670b88066a]

/home/buildbot/amd64-msan-clang-20/build/sql/mariadbd(handle_fatal_signal+0x509)[0x55670a6b6f49]

mysys/stacktrace.c:215(my_print_stacktrace)[0x556709a1fac9]

/lib/x86_64-linux-gnu/libc.so.6(+0x3c050)[0x7fe476619050]

sql/sql_class.h:4966(set_var_collation_client::update(THD*))[0x556709b33566]

sql/set_var.cc:750(sql_set_variables(THD*, List<set_var_base>*, bool))[0x556709b31bc4]

sql/sql_parse.cc:0(mysql_execute_command(THD*, bool))[0x556709dd20f4]

sql/sql_parse.cc:0(mysql_parse(THD*, char*, unsigned int, Parser_state*))[0x556709dbdd6f]

sql/sql_parse.cc:0(bootstrap(st_mysql_file*))[0x556709dbcb74]

sql/mysqld.cc:6107(mysqld_main(int, char**))[0x556709a36e60]

/lib/x86_64-linux-gnu/libc.so.6(+0x2724a)[0x7fe47660424a]

/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0x85)[0x7fe476604305]

/home/buildbot/amd64-msan-clang-20/build/sql/mariadbd(_start+0x21)[0x556709993671]

Connection ID (thread ID): 1

Status: NOT_KILLED

Query (0x70c0000043b0): SET NAMES latin1 COLLATE latin1_swedish_ci;

Optimizer switch: index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,duplicateweedout=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=on,cset_narrowing=on,sargable_casefold=on