Killed query reports ER_NOT_FORM_FILE for a table with virtual column expressions

Reproduce

--source include/have_debug_sync.inc

create table t1 (a int, b int as (a + 1) virtual);

insert into t1 (a) values (1);

flush tables;

connect con1, localhost, root;

let $con1_id= `select connection_id()`;

set debug_sync= 'TABLE_after_field_clone signal opening wait_for go';

send select * from t1;

connection default;

set debug_sync= 'now wait_for opening';

--replace_result $con1_id CON1_ID

eval kill query $con1_id;

connection con1;

--error ER_QUERY_INTERRUPTED

reap;

show warnings;

disconnect con1;

connection default;

set debug_sync= 'reset';

drop table t1;

Result

ERROR 70100: Query execution was interrupted

show warnings;

Level	Code	Message

Error	1317	Query execution was interrupted

Error	1065	Query was empty

Error	1033	Incorrect information in file: './test/t1.frm'

Expected

ERROR 70100: Query execution was interrupted

show warnings;

Level	Code	Message

Error	1317	Query execution was interrupted

Error	1065	Query was empty

The .frm is not corrupted: the query was killed while the table was being opened. ER_NOT_FORM_FILE must not be reported.

Notes

Expressions of virtual columns, DEFAULT and CHECK constraints are parsed from the .frm each time a new TABLE instance is created: open_table_from_share() calls parse_vcol_defs(), which calls unpack_vcol_info_from_frm(), which calls parse_sql(). Lex_input_stream::lex_one_token() checks thd->killed on each token, calls send_kill_message() and returns END_OF_INPUT, so the parse fails. unpack_vcol_info_from_frm() does not set *error_reported when parse_sql() fails, so open_table_from_share() sets OPEN_FRM_CORRUPTED and open_table_error() raises ER_NOT_FORM_FILE.

The main error stays the kill error, ER_NOT_FORM_FILE is an extra condition. In replication it gets into Last_SQL_Error and the error log via aggregate_da_errors() when a parallel slave worker is killed (STOP SLAVE, KILL, shutdown) while opening a table.

The same code is in 10.6, 10.11, 11.8, 12.3 and main.

Suspected, not reproduced: if the kill comes between tokens where the already read part is a valid expression (e.g. after `a` in `a` + 1), the grammar accepts END_OF_INPUT and parse_sql() succeeds, because the kill error is not fatal. The TABLE is then opened with a truncated expression and may be returned to the table cache.