bug#24956: 26.0.50; On Windows, setting PATH in compilation-environment has no effect

[Noam Postavsky <npostavs@users.sourceforge.net>]

tag 24956 confirmed
quit

On Wed, Nov 16, 2016 at 5:22 PM, Óscar Fuentes <ofv@wanadoo.es> wrote:
>
> emacs -Q. Evaluate:
>
> (let ((compilation-environment (list "PATH=d:\\foo")))
>   (compile "echo %PATH%"))
>
> The output is the original contents of PATH. Until recently (June, at
> least) it was possible to set PATH in compilation-environment and pass
> it to child processes. On GNU/Linux, it still is.

It seems that my change in 73f0715d "Keep w32 environment settings
internal only", had an unexpected effect on the way differently cased
environment variables are handled.

With latest master

(let ((process-environment (cons "PATH=d:\\foo" process-environment)))
  (call-process "cmd" nil '(t t) nil "/C" "echo %PATH%"))

inserts the original PATH contents, whereas

(let ((process-environment (cons "Path=d:\\foo" process-environment)))
  (call-process "cmd" nil '(t t) nil "/C" "echo %PATH%"))

inserts "d:\foo". In Emacs 25.1, or reverting the commit I mentioned,
the opposite occurs.