Re: Emacs 25.2, win64, env vars

[Stefan Monnier <monnier@iro.umontreal.ca>]

> 1 - do nothing. Possibly find a place to document the fact that under
> Windows, emacs will inherit variables from the starting shell and that some
> shells
> may provide case sensitive environment variables.
> 2 - remove the case insensitive comparison for WINDOWSNT in
> getenv_internal_1 and replace it with a case sensitive one because some
> shells may
> provide case sensitive environment variables . This will result in handling
> case sensitive environment variables even under Windows. I guess it would
> need some testing to ensure
> everything works as expected, under MSYS2 or Cygwin.
> 3 - apply the fix I offered (or another equivalent one ?)  because it makes
> the handling of environment variables case symetrical for setenv and
> getenv, and both are case insensitive.

There's also

4 - first lookup case-sensitively, then if that fails, lookup with
    case-fold.

Whichever behavior is chosen, there's a somewhat orthogonal issue that
needs to be addressed: detect the ambiguity and warn the user when it occurs.


        Stefan