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From: dwh@linuxprogrammer.org
To: git@vger.kernel.org
Subject: pkt-line and LF terminated lines of data
Date: Wed, 28 Apr 2021 15:22:19 -0700	[thread overview]
Message-ID: <20210428222219.GA982@localhost> (raw)

I was just reading the Documentation/technical/protocol-common.txt
description of the pkt-line format. One detail that is left out is how a
receiver of pkt-line encoded data determines if a line is binary data or
contains non-binary data.

The documentation says:

> A non-binary line SHOULD BE terminated by an LF, which if present MUST
> be included in the total length. Receivers MUST treat pkt-lines with
> non-binary data the same whether or not they contain the trailing LF
> (stripping the LF if present, and not complaining when it is missing).

It seems like a pkt-line with binary data could easily end with 0x0a
(LF) and a receiver would strip it off even though that is a legitimate
byte in the binary stream. I don't think receivers should be trying to
determine if the pkt-line is binary or non-binary and never strip off
any 0x0a bytes at the end of a pkt-line.

The client code that relies on the pkt-line receiver is where the logic
should reside that figures out what to do with strings that end with LF.
The pkt-line receiver just parses the pkg-line length, reads the correct
number of bytes and passes them along for further processing.

What am I missing? What should be added to this documentation that gives
more detail on when/why/how a pkt-line would be determined to be
non-binary and the LF stripping would occur?

Cheers!
Dave

             reply	other threads:[~2021-04-28 22:26 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-28 22:22 dwh [this message]
2021-04-29  0:12 ` pkt-line and LF terminated lines of data Ævar Arnfjörð Bjarmason
2021-04-29  2:08   ` brian m. carlson
2021-04-29  3:16 ` Junio C Hamano

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