nmh 1.8RC2, xlbiff, and $HOME

[Stephen Gildea]

I have investigated the failure of the xlbiff tests with nmh 1.8RC2.
(This is https://bugs.debian.org/1029752)

In one of the tests, xlbiff sets environment variable HOME to an empty
string and MH to a file containing a custom profile with an absolute Path.
With nmh 1.7.1, this environment works.

With nmh 1.8RC2, this environment fails with the error message
"environment variable HOME is empty".

You can see the change in behavior as follows:

$ printf 'Path: /tmp\n' > /tmp/mh-profile-minimal
$ HOME= MH=/tmp/mh-profile-minimal /usr/bin/mh/mhparam path


nmh 1.7.1:
/tmp

nmh 1.8RC2:
mhparam: environment variable HOME is empty


My analysis:

This is a regression.  HOME is used only to set the default profile
file to "$HOME/.mh_profile".  But nmh doesn't need HOME if MH is set.

A further documentation issue: mh-profile(5) does not specify the
treatment of a relative Path.  I expected it to be relative to the
directory of the profile file, but it seems to actually be relative to
HOME.

Whatever your decision, the choice should be documented.  If you decide to
keep Path relative to HOME, then HOME should be required to be non-empty if
(and only if!) Path is relative.  (nmh 1.7.1 used "/", which seems wrong.)

 < Stephen