MonetDB server crashes in merge_table_prune_and_unionize

[fuboat]

Describe the bug
MonetDB server crashes in merge_table_prune_and_unionize.

To Reproduce

 CREATE MERGE TABLE a (b int, subtable2 varchar(32)) PARTITION BY VALUES ON (b)  ;
 CREATE MERGE TABLE t1 (c int, d varchar(32)) PARTITION BY RANGE ON (c)  ;
 CREATE TABLE id (t1907060_1 int, age varchar(32))  ;
 ALTER TABLE a ADD TABLE id AS PARTITION IN ('1', '2', '3')  ;
 ALTER TABLE t1 ADD TABLE a AS PARTITION FROM '0' TO '100'  ;
 SELECT c, d FROM t1 ; 

Backtrace of the Crash

#0 0x7eff4132d1ff (merge_table_prune_and_unionize+0x2df)
#1 0x7eff4132ee82 (merge_table_prune_and_unionize+0x1f62)
#2 0x7eff4132cdd5 (rel_merge_table_rewrite_+0x6e5)
#3 0x7eff413081ef (rel_visitor_topdown+0x27f)
#4 0x7eff413085a5 (rel_visitor_topdown+0x635)
#5 0x7eff4132bb5b (rel_merge_table_rewrite+0x3b)
#6 0x7eff4132c2da (rel_optimizer+0x75a)
#7 0x7eff4128ff22 (sql_processrelation+0x82)
#8 0x7eff41099e1b (sql_symbol2relation+0x1bb)
#9 0x7eff410c6b84 (SQLparser+0x624)
#10 0x7eff410c5cbc (SQLengine_+0xa5c)
#11 0x7eff410c34fe (SQLengine+0x3e)
#12 0x7eff416412cf (runScenario+0x6f)
#13 0x7eff416424de (MSscheduleClient+0xb6e)
#14 0x7eff41779182 (doChallenge+0x132)
#15 0x7eff424a28a7 (thread_starter+0xc7)
#16 0x7eff40fbd609 (start_thread+0xd9)
#17 0x7eff40ee0133 (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