Conditional jump or move depends on uninitialised value in sel_arg_range_seq_next

$ perl ./mtr --valgrind main.subselect_mat_cost

main.subselect_mat_cost                  [ fail ]  Found warnings/errors in server log file!

        Test ended at 2020-01-15 18:46:14

line

==7420== Thread 6:

==7420== Conditional jump or move depends on uninitialised value(s)

==7420==    at 0xDF628B: sel_arg_range_seq_next(void*, st_key_multi_range*) (opt_range_mrr.cc:342)

==7420==    by 0xDFC8C0: records_in_column_ranges(PARAM*, unsigned int, SEL_ARG*) (opt_range.cc:3189)

==7420==    by 0xDFD50B: calculate_cond_selectivity_for_table(THD*, TABLE*, Item**) (opt_range.cc:3458)

==7420==    by 0x961CF5: make_join_statistics(JOIN*, List<TABLE_LIST>&, st_dynamic_array*) (sql_select.cc:5435)

==7420==    by 0x9561E1: JOIN::optimize_inner() (sql_select.cc:2235)

==7420==    by 0x953B97: JOIN::optimize() (sql_select.cc:1598)

==7420==    by 0x8D68E3: st_select_lex::optimize_unflattened_subqueries(bool) (sql_lex.cc:4187)

==7420==    by 0xAFFFDF: JOIN::optimize_unflattened_subqueries() (opt_subselect.cc:5512)

==7420==    by 0x958389: JOIN::optimize_stage2() (sql_select.cc:2797)

==7420==    by 0x9562DF: JOIN::optimize_inner() (sql_select.cc:2261)

==7420==    by 0x953B97: JOIN::optimize() (sql_select.cc:1598)

==7420==    by 0x95F023: mysql_select(THD*, TABLE_LIST*, unsigned int, List<Item>&, Item*, unsigned int, st_order*, st_order*, Item*, st_order*, unsigned long long, select_result*, st_select_lex_unit*, st_select_lex*) (sql_select.cc:4633)

==7420==    by 0x99C58B: mysql_explain_union(THD*, st_select_lex_unit*, select_result*) (sql_select.cc:26815)

==7420==    by 0x914426: execute_sqlcom_select(THD*, TABLE_LIST*) (sql_parse.cc:6299)

==7420==    by 0x909E02: mysql_execute_command(THD*) (sql_parse.cc:3899)

==7420==    by 0x918962: mysql_parse(THD*, char*, unsigned int, Parser_state*, bool, bool) (sql_parse.cc:7901)