Re: [PATCH 1/2] sha1_name: don't trigger detailed diagnosis for file arguments

[Matthieu Moy <Matthieu.Moy@grenoble-inp.fr>]

Junio C Hamano <gitster@pobox.com> writes:

> I am not so sure about that.  The "only-to-die" caller is not even
> expecting that the call to this codepath would successfully return.
>
> Or at least, it shouldn't.
>
> So it might not be a bad idea to actually catch this as a
> programming error and do
>
> 	if (only_to_die) {
>         	if (!ret)
>                 	die("BUG");
> 		diagnose_invalid_sha1_path(...);
> 	}

I disagree.

The only-to-die caller can expect that get_sha1_with_context_1 never
returns when called with only-to-die, but it's a stronger assumption to
expect that this particular place will trigger the failure.

In this case, the assumption is correct because there's a "return ret;"
a bit later in the code, but I don't think we should have to look at
this to check the correctness of the code (for example, if something
like "if (ret) try_some_fallback_method();" is later added before
"return ret;", then the assumption would become false).

My version reads as

  try something;
  if (it failed && I'm only here to report an error)
          report_error();

which I find easier to understand.

-- 
Matthieu Moy
http://www-verimag.imag.fr/~moy/