[PATCH] filter: set environment variable PYTHONIOENCODING to utf-8

[Jason at zx2c4.com (Jason A. Donenfeld)]

On Sun, Mar 12, 2017 at 6:51 PM, John Keeping <john at keeping.me.uk> wrote:
> While I'm inclined to agree with this, in this particular case we
> explicitly encode pages as UTF-8 so there is an argument that we should
> be telling child processes that UTF-8 is the correct encoding.

That's a compelling argument, actually.

>
> Maybe we should be looking to change LANG instead, but I'm not sure how
> reliably we can do that.

I'm more onboard with that. Does changing LANG influence the PYTHON
variable implicitly?

> Is it safe to do something like:
>
>         const char *lang = getenv("LANG");
>         struct strbuf sb = STRBUF_INIT;
>
>         if (!lang)
>                 lang = "C";
>         strbuf_addf(&sb, "%.*s.UTF-8",
>                     (int) (strchrnul(lang, '.') - lang), lang);
>         setenv("LANG", sb.buf);

That's probably not too bad, though I wonder if we could get away with
just explicitly setting a more generic UTF-8 instead of trying to read
the user's language preferences.