Fuzzer: Virtuoso 7.2.12 crashed at `cv_subq_ret`.
It can also be reproduced with Version 7.2.13-dev.3239-pthreads as of Mar 17 2024 (da40b02).

PoC:
```SQL
SELECT table_name FROM columns ORDER BY ( SELECT ( ( d ( ' ' ) + -1.000000 + 1 ) - ( 0 , 0.000000 ) + ( SELECT d ( ' ' ) + -1.000000 + 1 ) ) );
```

backtrace:
```c
#0 0x7243c5 (cv_subq_ret+0x45)
#1 0x7337c8 (sqlg_dfe_code+0x288)
#2 0x750cba (sqlg_dt_query_1+0x156a)
#3 0x733783 (sqlg_dfe_code+0x243)
#4 0x750cba (sqlg_dt_query_1+0x156a)
#5 0x751c97 (sqlg_top_1+0x107)
#6 0x716074 (sqlo_top_select+0x164)
#7 0x6bf21b (sql_stmt_comp+0x8bb)
#8 0x6c20b2 (sql_compile_1+0x1a62)
#9 0x7d5b40 (stmt_set_query+0x340)
#10 0x7d7a32 (sf_sql_execute+0x922)
#11 0x7d8dbe (sf_sql_execute_w+0x17e)
#12 0x7e1a7d (sf_sql_execute_wrapper+0x3d)
#13 0xe2a11c (future_wrapper+0x3fc)
#14 0xe31a1e (_thread_boot+0x11e)
#15 0x7f4f37645609 (start_thread+0xd9)
#16 0x7f4f37415353 (clone+0x43)
```

ways to reproduce (write poc to the file /tmp/test.sql first):
```bash
# remove the old one
docker container rm virtdb_test -f
# start virtuoso through docker
docker run --name virtdb_test -itd --env DBA_PASSWORD=dba  pkleef/virtuoso-opensource-7
# wait the server starting
sleep 10
# check whether the simple query works
echo "SELECT 1;" | docker exec -i virtdb_test isql 1111 dba
# run the poc
cat /tmp/test.sql | docker exec -i virtdb_test isql 1111 dba
```
Fuzzer: Virtuoso 7.2.12 crashed at `cv_subq_ret`
This is a GitHub Issue
repo:virtuoso-opensource
owner:openlink
Title : Fuzzer: Virtuoso 7.2.12 crashed at `cv_subq_ret`
Issue date:

--- start body ---
Fuzzer: Virtuoso 7.2.12 crashed at `cv_subq_ret`.
It can also be reproduced with Version 7.2.13-dev.3239-pthreads as of Mar 17 2024 (da40b02).

PoC:
```SQL
SELECT table_name FROM columns ORDER BY ( SELECT ( ( d ( ' ' ) + -1.000000 + 1 ) - ( 0 , 0.000000 ) + ( SELECT d ( ' ' ) + -1.000000 + 1 ) ) );
```

backtrace:
```c
#0 0x7243c5 (cv_subq_ret+0x45)
#1 0x7337c8 (sqlg_dfe_code+0x288)
#2 0x750cba (sqlg_dt_query_1+0x156a)
#3 0x733783 (sqlg_dfe_code+0x243)
#4 0x750cba (sqlg_dt_query_1+0x156a)
#5 0x751c97 (sqlg_top_1+0x107)
#6 0x716074 (sqlo_top_select+0x164)
#7 0x6bf21b (sql_stmt_comp+0x8bb)
#8 0x6c20b2 (sql_compile_1+0x1a62)
#9 0x7d5b40 (stmt_set_query+0x340)
#10 0x7d7a32 (sf_sql_execute+0x922)
#11 0x7d8dbe (sf_sql_execute_w+0x17e)
#12 0x7e1a7d (sf_sql_execute_wrapper+0x3d)
#13 0xe2a11c (future_wrapper+0x3fc)
#14 0xe31a1e (_thread_boot+0x11e)
#15 0x7f4f37645609 (start_thread+0xd9)
#16 0x7f4f37415353 (clone+0x43)
```

ways to reproduce (write poc to the file /tmp/test.sql first):
```bash
# remove the old one
docker container rm virtdb_test -f
# start virtuoso through docker
docker run --name virtdb_test -itd --env DBA_PASSWORD=dba  pkleef/virtuoso-opensource-7
# wait the server starting
sleep 10
# check whether the simple query works
echo "SELECT 1;" | docker exec -i virtdb_test isql 1111 dba
# run the poc
cat /tmp/test.sql | docker exec -i virtdb_test isql 1111 dba
```
--- end body ---
