Thanks to all of those who responded to my whitescreen/segfault problems.
It turns out I was 'allocing' memory for the newly created dir_cfg and for
an array of rbl_handler pointers, but not for each individual rbl_pointer
structure that the rbl_handler pointers pointed to.
Now that that's fixed,
I think I was able to answer my own question(s).
This link got me curious:
http://www.f-m-c.org/projects/apache/html/3_3Extending_Apache.html
I read what seemed to say that the merging of directories was done at the
beginning of the handling of a request. I re-worked my debug code to output
to