There's a bit of code in src/mac.c which sets the environment variable
INFOPATH if it's not already set, when Emacs is installed as a
self-contained application bundle.
Normally, Info-directory-list should be initialised based on
Info-default-directory-list. But because INFOPATH gets set behind the
user's back, this does not happen, and so Info-directory-list is set
based on INFOPATH. This is unexpected and confusing behaviour (at least
it was for me).
Would it be better to add the bundle's Info directory to
Info-default-directory-list, instead of playing around with INFOPATH?
Isn't this the sort of thing that Info-default-directory-list is