Can we assume HOME is defined in the environment?

[Jose E. Marchesi]

Hi people!

poke/poke.pk currently contains this code:

try map_load_path = getenv ("XDG_DATA_HOME") + map_load_path;
catch if E_inval { map_load_path = getenv ("HOME") + "/.local/share/poke:" + 
map_load_path; }

This basically means that poke will raise an unhandled exception if the
HOME environment variable is not defined.  This will prevent it from
starting.

Should we add a check there to not update the map_load_path with that
entry if HOME is not defined?  In other words: can we safely assume HOME
is defined?  I am thinking on mingw targets here..