Is this possible with a trivial patch? I'm not yet ready to upgrade all
nodes to Slony 1.2...

The 1.1.5 compile fails at:

gcc -g -O2 -pthread -I../.. -I/usr/include/postgresql/ -o slon slon.o
runtime_config.o local_listen.o remote_listen.o remote_worker.o
sync_thread.o cleanup_thread.o scheduler.o dbutils.o conf-file.o
confoptions.o misc.o -pthread -L/usr/lib/
-L/usr/lib/postgresql/8.2/lib/ -lpq -Wl,-rpath,/usr/lib/  -L/usr/lib/
-lpq
confoptions.o: In function `build_conf_variables': 
/root/slony1-1.1.5/src/slon/confoptions.c:115:
undefined reference to `pg_qsort' 
collect2: ld returned 1 exit status

Cheers,
Gavin.