Re: [GSoC PATCH v2 0/2] diff: handle UTF-8 chars in prefix when calculating diffstat width

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 27, 2026, 18:04 UTC
Message-ID: <xmqq5x7irrjq.fsf@gitster.g>
In-Reply-To: <cover.1772136203.git.lorenzo.pegorari2002@gmail.com>

LorenzoPegorari <lorenzo.pegorari2002@gmail.com> writes:

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> This patch aims to fix a bug where the calculation of the diffstat width
> incorrectly uses the strlen() of line_prefix instead of its actual
> display width.
>
> This patch addresses the NEEDSWORK item added by ce8529b2 (diff: leave
> NEEDWORK notes in show_stats() function, 2022-10-21).
>
> V2 DIFF:
> * Changed references from "ANSI char" to "UTF-8 char"

Is that correct? I thought these references are mostly about the ANSI color escape sequences that are used to paint strings in color e.g.,

    printf "This is shown in \033[31mRED\033[0m color\012"

uses "\033[31m" (use RED as the foreground color) and "\033[0m" (reset all styles and colors). The problem the NEEDSWORK comment talks about is that the code uses strlen() but these two sequences in the above example are 0-width as far as the terminal display width computation is concerned. And that is why we want to use utf8_strnwidth() with SKIP_ANSI bit on.

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>  diff.c                 | 12 ++++--------
>  t/b                    |  0
>  t/t4052-stat-output.sh | 30 ++++++++++++++++++++++++++++++
>  3 files changed, 34 insertions(+), 8 deletions(-)
>  create mode 100644 t/b

I doubt you meant to add a new file there ;-)