Re: [PATCH v2 1/2] format-patch: Add a config option format.from to set the default for --from

[Jeff King <peff@peff.net>]

On Sun, Aug 07, 2016 at 07:02:18PM -1000, Josh Triplett wrote:

> > Portability; some compilers choke on it. C89 allows trailing commas in
> > array initialization but _not_ in enums. Most compilers allow it anyway
> > (though gcc complains with -Wpedantic).
> > 
> > This definitely broke the build on real systems early in Git's history
> > (I think the AIX compiler was one culprit),
> 
> Thanks for the explanation.  I assume such compilers also don't accept
> C99?

Correct. We don't allow other C99 features like variadic macros, either
(there are some in the code base, but you'll note they can all be
conditionally disabled).

> Perhaps the next Git user survey could ask "what compiler (including
> version) do you use to compile Git", and perhaps "does it accept the
> following code:"?

Maybe. I'm not sure I would consider a lack of responses there to be a
definite sign. It seems that once every few years people on bizarre
systems come out of the woodwork and do a round of portability fixes,
and then problems accrue, and so on. So I'm not sure that the survey
would hit the right people in a timely manner.

I think the breaking point will be just declaring "look, C99 is N years
old; if your compiler can't handle it, that's now your problem". When
Git started, N was only 6. It's now 17.

-Peff