Re: [PATCH v2 2/2] [GSOC] ref-filter: add %(raw) atom

From: ZheNing Hu <adlternative@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: ZheNing Hu via GitGitGadget <gitgitgadget@gmail.com>,
	Git List <git@vger.kernel.org>,
	Christian Couder <christian.couder@gmail.com>,
	Hariom Verma <hariom18599@gmail.com>,
	Karthik Nayak <karthik.188@gmail.com>,
	Felipe Contreras <felipe.contreras@gmail.com>,
	Bagas Sanjaya <bagasdotme@gmail.com>, Jeff King <peff@peff.net>,
	Phillip Wood <phillip.wood123@gmail.com>
Subject: Re: [PATCH v2 2/2] [GSOC] ref-filter: add %(raw) atom
Date: Tue, 1 Jun 2021 19:05:58 +0800	[thread overview]
Message-ID: <CAOLTT8TP0kxp=MJw_kBifWjf9n69FWS8Mcxn0EZjsM69MdidHw@mail.gmail.com> (raw)
In-Reply-To: <xmqqa6o9ucyc.fsf@gitster.g>

Junio C Hamano <gitster@pobox.com> 于2021年6月1日周二 下午5:54写道：
>
> > Well, there seems to be no correction here. But is it true that memory
> > like "\0abc" is considered empty?
>
> That sample has 'a' or 'b' or 'c' that are clearly not part of an
> "empty" string and irrelevant.  After all, a string " abc" is not
> treated as empty in the original implementation, either.
>

In other words, we still need to look at each character of strbuf,
instead of stopping at NUL.

> You are treating a block of memory with e.g. " \000 " (SP NUL SP) as
> an "empty line" just like you do for "   " (SP SP SP), but I think we
> should treat it more like " \001 " or " \007 ", i.e. not an empty
> string at all.

OK. I understand it now: " \001 " is It’s like a block of space, but it’s
not truly "empty", "SP NUL SP" is same too, So the complete definition of
"empty" here should be: All characters are SP which do not contain NUL
or other characters.

Thanks.
--
ZheNing Hu