MonetDB server crashes in gc_col

[fuboat]

Describe the bug
MonetDB server crashes in gc_col.

To Reproduce

 CREATE MERGE TABLE t_base (dt_uom int, subtable1 int, a varchar(32), b real) PARTITION BY VALUES ON (a)  ;
 start transaction  ;
 ALTER TABLE t_base DROP COLUMN subtable1  ;
 ALTER TABLE nexttest DROP COLUMN cc  ; 

Backtrace of the Crash

#0 0x7f8ba1bce2de (gc_col+0xae)
#1 0x7f8ba1bcfeb5 (tc_gc_drop_col+0x35)
#2 0x7f8ba1b74e2d (sql_trans_rollback+0x48d)
#3 0x7f8ba1b88e02 (sql_trans_end+0x152)
#4 0x7f8ba1c0142d (mvc_rollback+0x4ad)
#5 0x7f8ba1c00444 (mvc_commit+0x254)
#6 0x7f8ba1a75b8c (SQLtransaction_commit+0x16c)
#7 0x7f8ba1f8829f (runMALsequence+0xf0f)
#8 0x7f8ba1f86f3e (runMAL+0xee)
#9 0x7f8ba1a34bf2 (SQLrun+0x142)
#10 0x7f8ba1a366b9 (SQLengineIntern+0xc9)
#11 0x7f8ba1a33399 (SQLengine_+0x1139)
#12 0x7f8ba1a304fe (SQLengine+0x3e)
#13 0x7f8ba1fae2cf (runScenario+0x6f)
#14 0x7f8ba1faf4de (MSscheduleClient+0xb6e)
#15 0x7f8ba20e6182 (doChallenge+0x132)
#16 0x7f8ba2e0f8a7 (thread_starter+0xc7)
#17 0x7f8ba192a609 (start_thread+0xd9)
#18 0x7f8ba184d133 (clone+0x43)

Software versions

• MonetDB version number: v11.49.1 (Dec2023)
• OS and version: Ubuntu 20.04
• From docker image monetdb/monetdb:Dec2023

An example of steps to reproduce in docker container (write the poc into /tmp/test.sql first):

docker container rm monetdb_test -f
docker run -e MDB_DB_ADMIN_PASS=monetdb --name monetdb_test -itd monetdb/monetdb:Dec2023
docker exec monetdb_test bash -c 'echo -n -e "user=monetdb\npassword=monetdb\n" > /root/.monetdb'

sleep 10
cat /tmp/test.sql | timeout 5s docker exec -i monetdb_test mclient monetdb     # run test case

if docker exec monetdb_test bash -c "grep '[m]server5' /proc/*/cmdline -lR"; then
    echo "[INFO] Server normal."
else
    echo "[CRASH] Mserver5 process does NOT exist."
fi

It can also be reproduced on the docker image monetdb/dev-builds:default.

Issue labeling
bug

[lrpereira]

Thanks @fuboat !

Fixed in Dec2023.