git@vger.kernel.org list mirror (unofficial, one of many)
 help / color / mirror / code / Atom feed
From: Junio C Hamano <gitster@pobox.com>
To: Jeff King <peff@peff.net>
Cc: "SZEDER Gábor" <szeder.dev@gmail.com>,
	"Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>,
	git@vger.kernel.org,
	"Johannes Schindelin" <johannes.schindelin@gmx.de>
Subject: Re: [PATCH v3 01/10] built-in add -i/-p: treat SIGPIPE as EOF
Date: Wed, 15 Jan 2020 10:32:59 -0800	[thread overview]
Message-ID: <xmqqblr4k1t0.fsf@gitster-ct.c.googlers.com> (raw)
In-Reply-To: <20200113183313.GA2087@coredump.intra.peff.net> (Jeff King's message of "Mon, 13 Jan 2020 13:33:13 -0500")

Jeff King <peff@peff.net> writes:

> On Mon, Jan 13, 2020 at 06:04:17PM +0100, SZEDER Gábor wrote:
>
>> After looking into it, the issue seems to be sending data to the
>> broken diffFilter process.  So in that test the diff is "filtered"
>> through 'echo too-short', which exits real fast, and doesn't read its
>> standard input at all (well, apart from e.g. the usual kernel
>> buffering that might happen on a pipe between the two processes).
>> Making sure that the diffFilter process reads all the data before
>> exiting, i.e. changing it to:
>> 
>>   test_config interactive.diffFilter "cat >/dev/null ; echo too-short" &&
>> 
>> made the test reliable, with over 2000 --stress repetitions, and that
>> with only a single "y" on 'git add's stdin.
>
> Yeah, I agree the test should be changed. What you wrote above was my
> first thought, too, but I think "sed 1d" is actually a more realistic
> test (and is shorter and one fewer process).

I am not sure what we are aiming for.  Are we making sure the
command behaves well in the hands of end users, who may write a
script that consumes only early parts of the input that is needed
for its use and stops reading, or are we just aiming to claim "all
our tests pass"?  I was hoping that we would be doing the former,
and I would understand if the suggestion were "sed 1q" for that
exact reason.

IOW, shouldn't we be fixing the part that drives the external
process, so that the test "passes" even with such a "broken" filter?

>> Now, merely tweaking the test is clearly insufficient, because we not
>> only want the test to be realiable, but we want 'git add' to die
>> gracefully when users out there mess up their configuration.

Yes, and I was hoping that we do not have to touch the test if we
did the latter.

> I really wish there was a way to set a handler for SIGPIPE that tells
> _which_ descriptor caused it. Because I think logic like "die if it was
> fd 1, ignore and let write() return EPIPE otherwise" is the behavior
> we'd like. But I don't think there's a portable way to do so.
>
> I've been tempted to say that we should just ignore SIGPIPE everywhere,
> and convert even copious-output programs like git-log to just check for
> errors (they could probably even just check ferror(stdout) for each
> commit we output, if we didn't want to touch every printf call).

Yeah, I share that temptation.

  reply	other threads:[~2020-01-15 18:33 UTC|newest]

Thread overview: 63+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-21 22:41 [PATCH 0/9] built-in add -p: add support for the same config settings as the Perl version Johannes Schindelin via GitGitGadget
2019-12-21 22:41 ` [PATCH 1/9] built-in add -p: support interactive.diffFilter Johannes Schindelin via GitGitGadget
2019-12-21 22:41 ` [PATCH 2/9] built-in add -p: handle diff.algorithm Johannes Schindelin via GitGitGadget
2019-12-21 22:41 ` [PATCH 3/9] terminal: make the code of disable_echo() reusable Johannes Schindelin via GitGitGadget
2019-12-21 22:41 ` [PATCH 4/9] terminal: accommodate Git for Windows' default terminal Johannes Schindelin via GitGitGadget
2019-12-21 22:41 ` [PATCH 5/9] terminal: add a new function to read a single keystroke Johannes Schindelin via GitGitGadget
2019-12-21 22:41 ` [PATCH 6/9] built-in add -p: respect the `interactive.singlekey` config setting Johannes Schindelin via GitGitGadget
2019-12-21 22:41 ` [PATCH 7/9] built-in add -p: handle Escape sequences in interactive.singlekey mode Johannes Schindelin via GitGitGadget
2019-12-21 22:41 ` [PATCH 8/9] built-in add -p: handle Escape sequences more efficiently Johannes Schindelin via GitGitGadget
2019-12-21 22:42 ` [PATCH 9/9] ci: include the built-in `git add -i` in the `linux-gcc` job Johannes Schindelin via GitGitGadget
2019-12-21 22:53   ` SZEDER Gábor
2019-12-25 11:56     ` Johannes Schindelin
2019-12-22  0:11   ` Junio C Hamano
2019-12-25 11:57     ` Johannes Schindelin
2019-12-24 18:23 ` [PATCH 0/9] built-in add -p: add support for the same config settings as the Perl version Junio C Hamano
2019-12-24 18:39   ` Junio C Hamano
2019-12-25  8:46     ` Simon Ruderich
2019-12-25 12:09     ` Johannes Schindelin
2019-12-25 12:02   ` Johannes Schindelin
2019-12-25 11:56 ` [PATCH v2 " Johannes Schindelin via GitGitGadget
2019-12-25 11:56   ` [PATCH v2 1/9] built-in add -p: support interactive.diffFilter Johannes Schindelin via GitGitGadget
2020-01-07 22:57     ` SZEDER Gábor
2020-01-13  6:47       ` Johannes Schindelin
2019-12-25 11:56   ` [PATCH v2 2/9] built-in add -p: handle diff.algorithm Johannes Schindelin via GitGitGadget
2019-12-25 11:56   ` [PATCH v2 3/9] terminal: make the code of disable_echo() reusable Johannes Schindelin via GitGitGadget
2019-12-25 11:56   ` [PATCH v2 4/9] terminal: accommodate Git for Windows' default terminal Johannes Schindelin via GitGitGadget
2019-12-25 11:56   ` [PATCH v2 5/9] terminal: add a new function to read a single keystroke Johannes Schindelin via GitGitGadget
2019-12-25 11:56   ` [PATCH v2 6/9] built-in add -p: respect the `interactive.singlekey` config setting Johannes Schindelin via GitGitGadget
2019-12-25 11:56   ` [PATCH v2 7/9] built-in add -p: handle Escape sequences in interactive.singlekey mode Johannes Schindelin via GitGitGadget
2019-12-25 11:56   ` [PATCH v2 8/9] built-in add -p: handle Escape sequences more efficiently Johannes Schindelin via GitGitGadget
2019-12-25 11:57   ` [PATCH v2 9/9] ci: include the built-in `git add -i` in the `linux-gcc` job Johannes Schindelin via GitGitGadget
2019-12-26 20:48     ` Derrick Stolee
2020-01-01 22:10       ` Johannes Schindelin
2019-12-26 20:45   ` [PATCH v2 0/9] built-in add -p: add support for the same config settings as the Perl version Junio C Hamano
2020-01-13  8:29   ` [PATCH v3 00/10] " Johannes Schindelin via GitGitGadget
2020-01-13  8:29     ` [PATCH v3 01/10] built-in add -i/-p: treat SIGPIPE as EOF Johannes Schindelin via GitGitGadget
2020-01-13 17:04       ` SZEDER Gábor
2020-01-13 18:33         ` Jeff King
2020-01-15 18:32           ` Junio C Hamano [this message]
2020-01-15 19:03             ` Jeff King
2020-01-14 12:47         ` Johannes Schindelin
2020-01-17 14:32         ` SZEDER Gábor
2020-01-17 18:58           ` Jeff King
2020-01-13  8:29     ` [PATCH v3 02/10] built-in add -p: support interactive.diffFilter Johannes Schindelin via GitGitGadget
2020-01-13  8:29     ` [PATCH v3 03/10] built-in add -p: handle diff.algorithm Johannes Schindelin via GitGitGadget
2020-01-13  8:29     ` [PATCH v3 04/10] terminal: make the code of disable_echo() reusable Johannes Schindelin via GitGitGadget
2020-01-13  8:29     ` [PATCH v3 05/10] terminal: accommodate Git for Windows' default terminal Johannes Schindelin via GitGitGadget
2020-01-13  8:29     ` [PATCH v3 06/10] terminal: add a new function to read a single keystroke Johannes Schindelin via GitGitGadget
2020-01-13  8:29     ` [PATCH v3 07/10] built-in add -p: respect the `interactive.singlekey` config setting Johannes Schindelin via GitGitGadget
2020-01-13  8:29     ` [PATCH v3 08/10] built-in add -p: handle Escape sequences in interactive.singlekey mode Johannes Schindelin via GitGitGadget
2020-01-13  8:29     ` [PATCH v3 09/10] built-in add -p: handle Escape sequences more efficiently Johannes Schindelin via GitGitGadget
2020-01-13  8:29     ` [PATCH v3 10/10] ci: include the built-in `git add -i` in the `linux-gcc` job Johannes Schindelin via GitGitGadget
2020-01-14 18:43     ` [PATCH v4 00/10] built-in add -p: add support for the same config settings as the Perl version Johannes Schindelin via GitGitGadget
2020-01-14 18:43       ` [PATCH v4 01/10] t3701: adjust difffilter test Johannes Schindelin via GitGitGadget
2020-01-14 18:43       ` [PATCH v4 02/10] built-in add -p: support interactive.diffFilter Johannes Schindelin via GitGitGadget
2020-01-14 18:43       ` [PATCH v4 03/10] built-in add -p: handle diff.algorithm Johannes Schindelin via GitGitGadget
2020-01-14 18:43       ` [PATCH v4 04/10] terminal: make the code of disable_echo() reusable Johannes Schindelin via GitGitGadget
2020-01-14 18:43       ` [PATCH v4 05/10] terminal: accommodate Git for Windows' default terminal Johannes Schindelin via GitGitGadget
2020-01-14 18:43       ` [PATCH v4 06/10] terminal: add a new function to read a single keystroke Johannes Schindelin via GitGitGadget
2020-01-14 18:43       ` [PATCH v4 07/10] built-in add -p: respect the `interactive.singlekey` config setting Johannes Schindelin via GitGitGadget
2020-01-14 18:43       ` [PATCH v4 08/10] built-in add -p: handle Escape sequences in interactive.singlekey mode Johannes Schindelin via GitGitGadget
2020-01-14 18:43       ` [PATCH v4 09/10] built-in add -p: handle Escape sequences more efficiently Johannes Schindelin via GitGitGadget
2020-01-14 18:43       ` [PATCH v4 10/10] ci: include the built-in `git add -i` in the `linux-gcc` job Johannes Schindelin via GitGitGadget

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: http://vger.kernel.org/majordomo-info.html

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=xmqqblr4k1t0.fsf@gitster-ct.c.googlers.com \
    --to=gitster@pobox.com \
    --cc=git@vger.kernel.org \
    --cc=gitgitgadget@gmail.com \
    --cc=johannes.schindelin@gmx.de \
    --cc=peff@peff.net \
    --cc=szeder.dev@gmail.com \
    --subject='Re: [PATCH v3 01/10] built-in add -i/-p: treat SIGPIPE as EOF' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

git@vger.kernel.org list mirror (unofficial, one of many)

This inbox may be cloned and mirrored by anyone:

	git clone --mirror https://public-inbox.org/git
	git clone --mirror http://ou63pmih66umazou.onion/git
	git clone --mirror http://czquwvybam4bgbro.onion/git
	git clone --mirror http://hjrcffqmbrq6wope.onion/git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V1 git git/ https://public-inbox.org/git \
		git@vger.kernel.org
	public-inbox-index git

Example config snippet for mirrors.
Newsgroups are available over NNTP:
	nntp://news.public-inbox.org/inbox.comp.version-control.git
	nntp://7fh6tueqddpjyxjmgtdiueylzoqt6pt7hec3pukyptlmohoowvhde4yd.onion/inbox.comp.version-control.git
	nntp://ie5yzdi7fg72h7s4sdcztq5evakq23rdt33mfyfcddc5u3ndnw24ogqd.onion/inbox.comp.version-control.git
	nntp://4uok3hntl7oi7b4uf4rtfwefqeexfzil2w6kgk2jn5z2f764irre7byd.onion/inbox.comp.version-control.git
	nntp://news.gmane.io/gmane.comp.version-control.git
 note: .onion URLs require Tor: https://www.torproject.org/

code repositories for project(s) associated with this inbox:

	https://80x24.org/mirrors/git.git

AGPL code for this site: git clone https://public-inbox.org/public-inbox.git