Dovecot now works perfectly. In spite of having a homeDirectory value for my test LDAP entry, I still needed the LDAP patch. For any foolish beginners like myself, the procedure for patch-less patching in FBSD is:

cd /usr/ports/mail/dovecot

If you have dovecot currently installed, then

make deinstall

If you have a work directory, then

make distclean

The next step reinstalls the work directory and any and all files that a patch might be applied to.

make patch

Move to the directory with the file you want to patch.

cd /usr/ports/mail/dovecot/work/dovecot-0.99.10/src/auth

Copy the patch file to the directory.

cp /path-to-patch-file/auth-no-homedir.patch .

Do something that allows you to view both the patch file and the file to be patched. In my case, that's

vim -o master-connection.c auth-no-homedir.patch

Find the line in the file to be patched that matches the line in the patch file marked with an "-". Replace it with the line in the patch file marked with a "+". Make absolutely sure that you have deleted only what should be deleted and have added everything that should be added, and in the correct location. Save and close.

cd /usr/ports/mail/dovecot

make install

Thank you Marco, and thank you very very much Timo for your time and effort.

Bob Hall