adding fields to pg_database

Hi,

I'm trying to add fields to pg_database in the system catalog. As long
as I add fixed-size fields before the VAR LENGTH ones, that's all fine.

But adding a VAR LENGTH (text) field initdb fails at: copying template1
to template0. The child process 'postgres' fails with signal 11. Strange
enough I suspect the segfault to occure at program termination (?). That
is just after the following initdb commands have been executed:

...

"REVOKE CREATE,TEMPORARY ON DATABASE template1 FROM public;\n",
"REVOKE CREATE,TEMPORARY ON DATABASE template0 FROM public;\n",

/*
* Finally vacuum to clean up dead rows in pg_database
*/
"VACUUM FULL pg_database;\n",

I've only added the fields in include/catalog/pg_database.h. Do I need
to fiddle other places?

Regards

Markus