Set an error code when a deadlock occurs in semi-consistent read. (Bug #31494)

innodb-semi-consistent: New tests for InnoDB semi-consistent reads.
Unfortunately, these will not trigger Bug #31494, because there merely
occur lock wait timeouts, not deadlocks.

mysql-test/innodb-semi-consistent-master.opt

+--innodb_locks_unsafe_for_binlog=true --innodb_lock_wait_timeout=2

mysql-test/innodb-semi-consistent.result

+set session transaction isolation level read committed;
+create table t1(a int not null) engine=innodb DEFAULT CHARSET=latin1;
+insert into t1 values (1),(2),(3),(4),(5),(6),(7);
+set autocommit=0;
+select * from t1 where a=3 lock in share mode;
+a
+3
+set session transaction isolation level read committed;
+set autocommit=0;
+update t1 set a=10 where a=5;
+ERROR HY000: Lock wait timeout exceeded; try restarting transaction
+commit;
+update t1 set a=10 where a=5;
+select * from t1 where a=2 for update;
+ERROR HY000: Lock wait timeout exceeded; try restarting transaction
+select * from t1 where a=2 limit 1 for update;
+a
+2
+update t1 set a=11 where a=6;
+update t1 set a=12 where a=2;
+ERROR HY000: Lock wait timeout exceeded; try restarting transaction
+update t1 set a=13 where a=1;
+ERROR HY000: Lock wait timeout exceeded; try restarting transaction
+commit;
+update t1 set a=14 where a=1;
+commit;
+select * from t1;
+a
+14
+2
+3
+4
+10
+11
+7
+drop table t1;

mysql-test/innodb-semi-consistent.test

+-- source include/not_embedded.inc
+-- source include/have_innodb.inc
+
+# basic tests of semi-consistent reads
+
+connect (a,localhost,root,,);
+connect (b,localhost,root,,);
+connection a;
+set session transaction isolation level read committed;
+create table t1(a int not null) engine=innodb DEFAULT CHARSET=latin1;
+insert into t1 values (1),(2),(3),(4),(5),(6),(7);
+set autocommit=0;
+# this should lock the entire table
+select * from t1 where a=3 lock in share mode;
+connection b;
+set session transaction isolation level read committed;
+set autocommit=0;
+-- error ER_LOCK_WAIT_TIMEOUT
+update t1 set a=10 where a=5;
+connection a;
+commit;
+connection b;
+update t1 set a=10 where a=5;
+connection a;
+-- error ER_LOCK_WAIT_TIMEOUT
+select * from t1 where a=2 for update;
+# this should lock the records (1),(2)
+select * from t1 where a=2 limit 1 for update;
+connection b;
+update t1 set a=11 where a=6;
+-- error ER_LOCK_WAIT_TIMEOUT
+update t1 set a=12 where a=2;
+-- error ER_LOCK_WAIT_TIMEOUT
+update t1 set a=13 where a=1;
+connection a;
+commit;
+connection b;
+update t1 set a=14 where a=1;
+commit;
+connection a;
+select * from t1;
+drop table t1;
+
+connection default;
+disconnect a;
+disconnect b;

row/row0sel.c

@@ -4003,6 +4003,7 @@ row_search_for_mysql(
 			mutex_enter(&kernel_mutex);
 			if (trx->was_chosen_as_deadlock_victim) {
 				mutex_exit(&kernel_mutex);
+				err = DB_DEADLOCK;
 
 				goto lock_wait_or_error;
 			}