From: Johannes Schindelin <Johannes.Schindelin@gmx•de>
To: phillip.wood@dunelm•org.uk
Cc: Johannes Schindelin via GitGitGadget <gitgitgadget@gmail•com>,
git@vger•kernel.org
Subject: Re: [PATCH 1/3] sideband: mask control characters
Date: Tue, 2 Dec 2025 16:43:54 +0100 (CET) [thread overview]
Message-ID: <7fa83a64-95f3-9ca8-537e-12a7f919d8ae@gmx.de> (raw)
In-Reply-To: <f2ce08c4-f70e-487a-8dd9-286ee5bc683d@gmail.com>
Hi Phillip,
On Wed, 15 Jan 2025, Phillip Wood wrote:
> Just a couple of small comments
>
> On 14/01/2025 18:19, Johannes Schindelin via GitGitGadget wrote:
> > From: Johannes Schindelin <johannes.schindelin@gmx•de>
> >
> > +static void strbuf_add_sanitized(struct strbuf *dest, const char *src, int
> > n)
> > +{
> > + strbuf_grow(dest, n);
> > + for (; n && *src; src++, n--) {
> > + if (!iscntrl(*src) || *src == '\t' || *src == '\n')
>
> Isn't it a bug to pass '\n' to maybe_colorize_sideband() ?
While a band 2 message is indeed split by newlines and fed to this
function line by line, which is the case for a long time already: since
ed1902ef5c6 (cope with multiple line breaks within sideband progress
messages, 2007-10-16), the same is not true for band 3 messages: They pass
the entire message in one go (and for multi-line payload, only the first
line is prefixed with `remote:`, which is arguably a bug, but not one that
is within this here patch series' scope).
See
https://gitlab.com/git-scm/git/-/blob/v2.52.0/sideband.c#L191 and
https://gitlab.com/git-scm/git/-/blob/v2.52.0/sideband.c#L176,
respectively.
So no, I don't think that we can currently consider it a bug to pass `\n`
as part of the `src` parameter to `maybe_colorize_sideband()`.
> > + strbuf_addch(dest, *src);
> > + else {
> > + strbuf_addch(dest, '^');
> > + strbuf_addch(dest, 0x40 + *src);
>
> This will escape DEL ('\x7f') as "^\xbf" which is invalid in utf-8 locales.
> Perhaps we could use "^?" for that instead.
Good point! This seems to be the historical way to escape DEL, probably
because 0x3f ('?') is 0x7f + 0x40 truncated to 7 bits. I'll do this in the
next iteration:
-- snip --
diff --git a/sideband.c b/sideband.c
index f613d4d6cc3..684621579fd 100644
--- a/sideband.c
+++ b/sideband.c
@@ -175,7 +175,7 @@ static void strbuf_add_sanitized(struct strbuf *dest, const char *src, int n)
n -= i;
} else {
strbuf_addch(dest, '^');
- strbuf_addch(dest, 0x40 + *src);
+ strbuf_addch(dest, *src == 0x7f ? '?' : 0x40 + *src);
}
}
}
-- snap --
>
> > +test_expect_success 'disallow (color) control sequences in sideband' '
> > + write_script .git/color-me-surprised <<-\EOF &&
> > + printf "error: Have you \\033[31mread\\033[m this?\\n" >&2
> > + exec "$@"
> > + EOF
> > + test_config_global uploadPack.packObjectshook ./color-me-surprised &&
> > + test_commit need-at-least-one-commit &&
> > + git clone --no-local . throw-away 2>stderr &&
> > + test_decode_color <stderr >decoded &&
> > + test_grep ! RED decoded
>
> I'd be happier if we used test_cmp() here so that we check that the sanitized
> version matches what we expect and the test does not pass if there a typo in
> the script above stops it from writing the SGR code for red.
I often debug test failures in Git's test suite and one of the most
annoying category of test failures is when test cases expect byte-wise
exact Git output that changed for totally legitimate reasons [*1*].
Even worse: In many of those instances, the _intent_ of the check is not
even clear from that `test_cmp` and has to be reconstructed, a boring,
tedious task with little benefit to show for the effort.
I much prefer tests like this one, where a precise `test_grep` states
exactly what it expects to be present, or missing. The intent of such a
command is much clearer than that of `test_cmp expect actual`.
So, much as I appreciate your suggestion, I would prefer to keep the code
as-is.
Ciao,
Johannes
Footnote *1*: This really is not hypothetical. I had to battle quite a bit
with unstable compression sizes that are part of a `test_cmp` comparison,
https://github.com/git-for-windows/git/pull/5926#issuecomment-3486556940
shows a bit of the problems but is very shy about providing the specific
number of days I spent on addressing this issue. In hindsight, I should
have spent at most two hours on converting that from a byte-wise
comparison to a qualitative comparison.
next prev parent reply other threads:[~2025-12-02 15:43 UTC|newest]
Thread overview: 85+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-14 18:19 [PATCH 0/3] Sanitize sideband channel messages Johannes Schindelin via GitGitGadget
2025-01-14 18:19 ` [PATCH 1/3] sideband: mask control characters Johannes Schindelin via GitGitGadget
2025-01-15 14:49 ` Phillip Wood
2025-12-02 15:43 ` Johannes Schindelin [this message]
2025-01-15 15:17 ` Andreas Schwab
2025-01-15 16:24 ` Junio C Hamano
2025-01-14 18:19 ` [PATCH 2/3] sideband: introduce an "escape hatch" to allow " Johannes Schindelin via GitGitGadget
2025-01-14 18:19 ` [PATCH 3/3] sideband: do allow ANSI color sequences by default Johannes Schindelin via GitGitGadget
2025-01-14 22:50 ` [PATCH 0/3] Sanitize sideband channel messages brian m. carlson
2025-01-16 6:45 ` Junio C Hamano
2025-01-28 16:03 ` Ondrej Pohorelsky
2025-01-31 17:55 ` Junio C Hamano
2025-12-02 14:11 ` Johannes Schindelin
2025-12-03 0:47 ` brian m. carlson
2025-12-03 8:04 ` Johannes Schindelin
2025-01-15 14:49 ` Phillip Wood
2025-12-02 14:56 ` Johannes Schindelin
2025-12-17 14:23 ` [PATCH v2 0/4] " Johannes Schindelin via GitGitGadget
2025-12-17 14:23 ` [PATCH v2 1/4] sideband: mask control characters Johannes Schindelin via GitGitGadget
2026-01-09 12:38 ` Patrick Steinhardt
2026-01-16 19:29 ` Johannes Schindelin
2025-12-17 14:23 ` [PATCH v2 2/4] sideband: introduce an "escape hatch" to allow " Johannes Schindelin via GitGitGadget
2025-12-18 2:22 ` Junio C Hamano
2025-12-18 17:59 ` Johannes Schindelin
2025-12-19 13:33 ` Junio C Hamano
2026-01-16 19:25 ` Johannes Schindelin
2026-01-09 12:38 ` Patrick Steinhardt
2025-12-17 14:23 ` [PATCH v2 3/4] sideband: do allow ANSI color sequences by default Johannes Schindelin via GitGitGadget
2026-01-09 12:38 ` Patrick Steinhardt
2026-01-16 19:38 ` Johannes Schindelin
2025-12-17 14:23 ` [PATCH v2 4/4] sideband: add options to allow more control sequences to be passed through Johannes Schindelin via GitGitGadget
2026-01-09 12:38 ` Patrick Steinhardt
2026-01-10 17:26 ` brian m. carlson
2026-01-15 21:14 ` Jeff King
2026-01-15 21:36 ` Junio C Hamano
2026-01-15 23:12 ` Johannes Schindelin
2026-01-16 6:45 ` Patrick Steinhardt
2026-01-16 12:12 ` Ondrej Pohorelsky
2026-01-16 15:21 ` Junio C Hamano
2026-01-16 18:46 ` Johannes Schindelin
2026-01-16 19:24 ` Junio C Hamano
2026-01-19 7:20 ` Patrick Steinhardt
2026-01-19 22:16 ` brian m. carlson
2026-01-20 2:41 ` D. Ben Knoble
2026-01-20 17:05 ` Junio C Hamano
2026-01-20 19:31 ` Jeff King
2026-01-20 20:11 ` Junio C Hamano
2026-01-21 7:39 ` Patrick Steinhardt
2026-01-22 12:29 ` Johannes Schindelin
2026-01-22 17:58 ` Junio C Hamano
2026-01-15 23:10 ` brian m. carlson
2026-02-03 1:11 ` Junio C Hamano
2026-02-03 7:12 ` Johannes Schindelin
2026-02-03 19:00 ` Junio C Hamano
2026-02-04 19:35 ` Junio C Hamano
2026-01-16 19:47 ` Johannes Schindelin
2026-01-16 22:26 ` [PATCH v3 0/5] Sanitize sideband channel messages Johannes Schindelin via GitGitGadget
2026-01-16 22:26 ` [PATCH v3 1/5] sideband: mask control characters Johannes Schindelin via GitGitGadget
2026-01-16 22:26 ` [PATCH v3 2/5] sideband: introduce an "escape hatch" to allow " Johannes Schindelin via GitGitGadget
2026-01-16 22:26 ` [PATCH v3 3/5] sideband: do allow ANSI color sequences by default Johannes Schindelin via GitGitGadget
2026-01-16 22:26 ` [PATCH v3 4/5] sideband: add options to allow more control sequences to be passed through Johannes Schindelin via GitGitGadget
2026-01-16 22:26 ` [PATCH v3 5/5] sideband: offer to configure sanitizing on a per-URL basis Johannes Schindelin via GitGitGadget
2026-01-16 22:32 ` [PATCH v3 0/5] Sanitize sideband channel messages Johannes Schindelin
2026-02-03 10:17 ` [PATCH v4 0/6] " Johannes Schindelin via GitGitGadget
2026-02-03 10:17 ` [PATCH v4 1/6] sideband: mask control characters Johannes Schindelin via GitGitGadget
2026-02-03 10:17 ` [PATCH v4 2/6] sideband: introduce an "escape hatch" to allow " Johannes Schindelin via GitGitGadget
2026-02-03 10:17 ` [PATCH v4 3/6] sideband: do allow ANSI color sequences by default Johannes Schindelin via GitGitGadget
2026-02-03 10:18 ` [PATCH v4 4/6] sideband: add options to allow more control sequences to be passed through Johannes Schindelin via GitGitGadget
2026-02-03 10:18 ` [PATCH v4 5/6] sideband: offer to configure sanitizing on a per-URL basis Johannes Schindelin via GitGitGadget
2026-02-03 10:18 ` [PATCH v4 6/6] sideband: delay sanitizing by default to Git v3.0 Johannes Schindelin via GitGitGadget
2026-02-04 19:26 ` [PATCH v4 0/6] Sanitize sideband channel messages Junio C Hamano
2026-02-05 14:48 ` Junio C Hamano
2026-02-13 23:50 ` Junio C Hamano
2026-03-02 18:11 ` [PATCH 0/3] Sanitizing sideband output Junio C Hamano
2026-03-02 18:11 ` [PATCH 1/3] sideband: drop 'default' configuration Junio C Hamano
2026-03-02 18:11 ` [PATCH 2/3] sideband: delay sanitizing by default to Git v3.0 Junio C Hamano
2026-03-02 18:11 ` [PATCH 3/3] sideband: conditional documentation fix Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 0/7] Sanitizing sideband output Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 1/7] sideband: mask control characters Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 2/7] sideband: introduce an "escape hatch" to allow " Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 3/7] sideband: do allow ANSI color sequences by default Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 4/7] sideband: add options to allow more control sequences to be passed through Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 5/7] sideband: offer to configure sanitizing on a per-URL basis Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 6/7] sideband: drop 'default' configuration Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 7/7] sideband: delay sanitizing by default to Git v3.0 Junio C Hamano
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