[Toybox] [PATCH] Fix wcwidth(3) on Mac.

[Rob Landley]

On 11/22/19 4:37 PM, enh via Toybox wrote:
> The Mac doesn't support "C.UTF-8"

Of course not. Sigh.

> (and toybox ignores the setlocale(3) failure),

The problem is what would I _do_ with it? ("Never test for an error condition
you don't know how to handle." - somebody named Steinbach.)

> leading to numerous test failures because wcwidth(3)
> always returns -1 for non-ASCII in the default C locale.

Alas, an area where my desire to support and my ability to test are far apart.

> Our choices are:
> 1. Always use "" (the environment).
> 2. Always use "en_US.UTF-8" (the closest to "C.UTF-8" supported on Macs).
> 3. Continue to use "C.UTF-8" elsewhere but one of the above on Macs.
> 
> I've gone with #1 because it's the default advice for setlocale(3),
> and it's probably closest to the user's intentions. Every OS I'm
> aware of has $LANG set to <something>.UTF-8 these days, and has
> done for a decade now.

Sigh. I was trying to force utf8 support because there's no reason not to do
that these days, and due to the stupid way localization was introduced there's
no way to enable utf8 without specifying "I mean _german_ UTF8, just like I
meant german ascii"...

> Note though that we'd also need to change LC_CTYPE to LC_ALL if we
> also want strerror(3) to be localized. For now, despite this
> setlocale(3) call, you'll still get "C" locale error messages.

While I do explicitly want localized error messages, the various "insert commas
into printed numbers and don't consider . a decimal separator" behavioral
changes seem like bugs in waiting (I don't even know what all the side effects
_are_ let alone have regression tests for them).

Which of the 8 gazillion locale micromanagements is "strerr output" under?

> ---
>  main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Hmmm... maybe it can do this as the fallback?

  if (!setlocale("c.utf8")) setlocale("");

(This is _so_ not my area of expertise, happy to be corrected here. But I want
utf8 support in initramfs or booting from a rescue USB stick where I haven't got
a full environment set up yet, which is why it was doing that in the first place...)

Rob