Re: [PATCH] builtin/receive-pack: dead initializer for retval in check_nonce

From: Junio C Hamano <gitster@pobox.com>
Date: Oct 22, 2018, 03:35 UTC
Message-ID: <xmqqzhv6wt4n.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20181020164526.GA1077@tor.lan>

Torsten Bögershausen <tboegi@web.de> writes:

Show 10 quoted lines

> Initializing a variable to "BAD" in the beginning can be a good thing
> for two reasons:
> - There is a complex if-elseif chain, which should set retval
>   in any case, this is at least what I expect taking a very quick look at the
>   code:
> ...
> # The second reason is that some compilers don't understand this complex
> # stuff either, and through out a warning, like
> # "retval may be uninitialized" or something in that style.
> # This is very compiler dependent.

And to help humans that unless some if/else chain explicitly says it is OK, the caller receives BAD by default. In other words, it is being defensive.

At least that was the reasoning behind the original code that did not support SLOP.

> So yes, the current code may seem to be over-eager and ask for
> optimization, but we don't gain more that a couple of nano-seconds
> or so.  The good thing is that we have the code a little bit more
> robust, when changes are done in the future.

True.