From: LorenzoPegorari Date: Fri, 27 Feb 2026 16:01:07 GMT Subject: [GSoC PATCH v2 0/2] diff: handle UTF-8 chars in prefix when calculating diffstat width Message-ID: In-Reply-To: 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" * Compacted the 2 test scripts in a single script, that I placed in the already existing test file t4052, which "tests --stat output for various commands" * Added many of the changes suggested to me by Junio C Hamano [1], in order to make the test easier to read and to debug * Added a descriptive comment for the test script, and a more complete commit message to describe the goal of the test [1]: https://lore.kernel.org/git/xmqqikbmk86b.fsf@gitster.g/ LorenzoPegorari (2): diff: handle UTF-8 chars in prefix when calculating diffstat width t4052: add test for diffstat width when prefix contains UTF-8 chars diff.c | 12 ++++-------- t/b | 0 t/t4052-stat-output.sh | 30 ++++++++++++++++++++++++++++++ 3 files changed, 34 insertions(+), 8 deletions(-) create mode 100644 t/b Range-diff against v1: 1: a798eda511 ! 1: 9e8161a700 diff: handle ANSI chars in prefix when calculating diffstat width @@ Metadata Author: LorenzoPegorari ## Commit message ## - diff: handle ANSI chars in prefix when calculating diffstat width + diff: handle UTF-8 chars in prefix when calculating diffstat width The diffstat width is calculated by taking the terminal width and - incorrectly subtracting the strlen() of line_prefix, instead of the - actual display width of line_prefix (which may contain ANSI chars). + incorrectly subtracting the `strlen()` of `line_prefix`, instead of the + actual display width of `line_prefix`, which may contain UTF-8 + characters (e.g., ANSI-colored strings in `log --graph --stat`). - Utilize the display width instead, obtained via utf8_strnwidth() with - the flag to skip ANSI chars. + Utilize the display width instead, obtained via `utf8_strnwidth()` with + the flag `skip_ansi`. Signed-off-by: LorenzoPegorari @@ diff.c: static void show_stats(struct diffstat_t *data, struct diff_options *opt /* - * We have width = stat_width or term_columns() columns total. -+ * We have width = stat_width or term_columns() columns total -+ * minus the length of line_prefix skipping ANSI chars to get the -+ * display width (e.g., to skip ANSI-colored strings in "log --graph"). ++ * We have width = stat_width or term_columns() columns total minus the ++ * length of line_prefix skipping UTF-8 chars to get the display width ++ * (e.g., to skip ANSI-colored strings in "log --graph --stat"). * We want a maximum of min(max_len, stat_name_width) for the name part. * We want a maximum of min(max_change, stat_graph_width) for the +- part. * We also need 1 for " " and 4 + decimal_width(max_change) 2: ce25150593 < -: ---------- t4074: add test for diffstat width when prefix contains ANSI chars -: ---------- > 2: 984fa10d72 t4052: add test for diffstat width when prefix contains UTF-8 chars -- 2.43.0