From: Lars Schneider <larsxschneider@gmail.com>
To: Jeff King <peff@peff.net>
Cc: git@vger.kernel.org, gitster@pobox.com, jnareb@gmail.com,
mlbright@gmail.com, e@80x24.org, Johannes.Schindelin@gmx.de,
ben@wijen.net
Subject: Re: [PATCH v5 03/15] pkt-line: add `gentle` parameter to format_packet()
Date: Wed, 10 Aug 2016 15:59:19 +0200 [thread overview]
Message-ID: <982CD9A4-E155-4DEE-9B47-BCEA4F0C493C@gmail.com> (raw)
In-Reply-To: <20160810133745.wagccvvf35o3pbwb@sigill.intra.peff.net>
> On 10 Aug 2016, at 15:37, Jeff King <peff@peff.net> wrote:
>
> On Wed, Aug 10, 2016 at 03:29:26PM +0200, Lars Schneider wrote:
>
>>
>>> On 10 Aug 2016, at 15:15, Jeff King <peff@peff.net> wrote:
>>>
>>> On Wed, Aug 10, 2016 at 03:03:59PM +0200, larsxschneider@gmail.com wrote:
>>>
>>>> From: Lars Schneider <larsxschneider@gmail.com>
>>>>
>>>> format_packet() dies if the caller wants to format a packet larger than
>>>> LARGE_PACKET_MAX. Certain callers might prefer an error response instead.
>>>
>>> I am not sure I agree here. Certainly I see the usefulness of gently
>>> handling a failure to write(). But if you are passing in too-large
>>> buffers, isn't that a bug in the program?
>>>
>>> How would you recover, except by splitting up the content? That might
>>> not be possible depending on how you are using the pkt-lines. And even
>>> if it is, wouldn't it be simpler to split it up before sending it to
>>> format_packet()?
>>
>> Good argument. I agree - this patch should be dropped.
>
> Actually, after reading further, one thought did occur to me. Let's say
> you are writing to a smudge filter, and one of the header packets you
> send has the filename in it. So you might do something like:
>
> if (packet_write_fmt_gently(fd, "filename=%s", filename) < 0) {
> if (filter_required)
> die(...);
> else
> return -1; /* we tried our best; skip smudge */
> }
>
> The "recovery" there is not to try sending again, but rather to give up.
> And that is presumably a sane outcome for somebody who tries to checkout
> a filename larger than 64K.
Yes!
> It does still feel a little weird that you cannot tell the difference
> between a write() error and bad input. Because you really might want to
> do something different between the two. Like:
>
> #define MAX_FILENAME (PKTLINE_DATA_MAXLEN - strlen("filename"))
>
> if (filename > MAX_FILENAME) {
> warning("woah, that name is ridiculous; truncating");
> ret = packet_write_fmt_gently(fd, "%.*s", MAX_FILENAME, filename);
> } else
> ret = packet_write_fmt_gently(fd, "%s", filename);
I can do that. However, I wouldn't truncate the filename as this
might create a weird outcome. I would just let the filter fail.
OK?
- Lars
next prev parent reply other threads:[~2016-08-10 21:14 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20160803164225.46355-1-larsxschneider@gmail.com/>
2016-08-10 13:03 ` [PATCH v5 00/15] Git filter protocol larsxschneider
2016-08-10 13:03 ` [PATCH v5 01/15] pkt-line: extract set_packet_header() larsxschneider
2016-08-10 13:03 ` [PATCH v5 02/15] pkt-line: call packet_trace() only if a packet is actually send larsxschneider
2016-08-10 13:13 ` Jeff King
2016-08-10 13:24 ` Lars Schneider
2016-08-10 13:30 ` Jeff King
2016-08-10 13:51 ` Lars Schneider
2016-08-10 14:33 ` Jeff King
2016-08-10 13:03 ` [PATCH v5 03/15] pkt-line: add `gentle` parameter to format_packet() larsxschneider
2016-08-10 13:15 ` Jeff King
2016-08-10 13:29 ` Lars Schneider
2016-08-10 13:37 ` Jeff King
2016-08-10 13:59 ` Lars Schneider [this message]
2016-08-10 14:34 ` Jeff King
2016-08-10 13:04 ` [PATCH v5 04/15] pkt-line: add packet_write_gently() larsxschneider
2016-08-10 13:28 ` Jeff King
2016-08-10 13:36 ` Lars Schneider
2016-08-10 13:40 ` Jeff King
2016-08-10 17:17 ` Junio C Hamano
2016-08-10 17:49 ` Lars Schneider
2016-08-10 18:21 ` Junio C Hamano
2016-08-10 19:15 ` Lars Schneider
2016-08-10 13:04 ` [PATCH v5 05/15] pkt-line: add packet_write_gently_fmt() larsxschneider
2016-08-10 13:43 ` Jeff King
2016-08-10 14:10 ` Lars Schneider
2016-08-10 15:01 ` Jeff King
2016-08-10 17:18 ` Junio C Hamano
2016-08-10 17:53 ` Lars Schneider
2016-08-10 18:42 ` Junio C Hamano
2016-08-10 13:04 ` [PATCH v5 06/15] pkt-line: add packet_flush_gently() larsxschneider
2016-08-10 13:04 ` [PATCH v5 07/15] pkt-line: add functions to read/write flush terminated packet streams larsxschneider
2016-08-10 13:04 ` [PATCH v5 08/15] pkt-line: rename packet_write() to packet_write_fmt() larsxschneider
2016-08-10 13:04 ` [PATCH v5 09/15] pack-protocol: fix maximum pkt-line size larsxschneider
2016-08-10 13:04 ` [PATCH v5 10/15] convert: quote filter names in error messages larsxschneider
2016-08-10 13:04 ` [PATCH v5 11/15] convert: modernize tests larsxschneider
2016-08-10 13:04 ` [PATCH v5 12/15] convert: generate large test files only once larsxschneider
2016-08-10 13:04 ` [PATCH v5 13/15] convert: make apply_filter() adhere to standard Git error handling larsxschneider
2016-08-10 13:04 ` [PATCH v5 14/15] convert: add filter.<driver>.process option larsxschneider
2016-08-12 16:33 ` Stefan Beller
2016-08-12 16:38 ` Jeff King
2016-08-12 16:48 ` Stefan Beller
2016-08-12 17:08 ` Lars Schneider
2016-08-12 17:13 ` Junio C Hamano
2016-08-12 17:21 ` Lars Schneider
2016-08-12 18:03 ` Junio C Hamano
2016-08-12 16:59 ` Lars Schneider
2016-08-12 17:07 ` Stefan Beller
2016-08-12 17:14 ` Lars Schneider
2016-08-10 13:04 ` [PATCH v5 15/15] read-cache: make sure file handles are not inherited by child processes larsxschneider
2016-08-18 14:23 ` Johannes Schindelin
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