For the record, I also tried this:
# /etc/passwd: umask set in GECOS
foo:x:1020:1020:,,,,umask=002:/home/foo:/bin/bash
# /etc/pam.d/common-session
session required pam_unix.so
session optional pam_umask.so
with exactly the same results, e.g. nothing useful.
--
"Oh, look: rocks!"
-- Doctor Who, "Destiny of the Daleks"