From 1a9df8de368cbebd881336f64e424422f3dbb993 Mon Sep 17 00:00:00 2001 From: LorenzoPegorari Date: Fri, 27 Feb 2026 22:45:19 +0100 Subject: [PATCH 1/2] diff: handle ANSI escape codes 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 escape codes (e.g., ANSI-colored strings in `log --graph --stat`). Utilize the display width instead, obtained via `utf8_strnwidth()` with the flag `skip_ansi`. Signed-off-by: LorenzoPegorari Signed-off-by: Junio C Hamano --- diff.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/diff.c b/diff.c index a1961526c0..9c848ec5db 100644 --- a/diff.c +++ b/diff.c @@ -2713,7 +2713,9 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options) count = i; /* where we can stop scanning in data->files[] */ /* - * 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 escape codes to get the display + * width (e.g., 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) @@ -2740,14 +2742,8 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options) * separators and this message, this message will "overflow" * making the line longer than the maximum width. */ - - /* - * NEEDSWORK: line_prefix is often used for "log --graph" output - * and contains ANSI-colored string. utf8_strnwidth() should be - * used to correctly count the display width instead of strlen(). - */ if (options->stat_width == -1) - width = term_columns() - strlen(line_prefix); + width = term_columns() - utf8_strnwidth(line_prefix, strlen(line_prefix), 1); else width = options->stat_width ? options->stat_width : 80; number_width = decimal_width(max_change) > number_width ? From 064b869efc50be2557015665bc3dc8ac9008a6e4 Mon Sep 17 00:00:00 2001 From: LorenzoPegorari Date: Fri, 27 Feb 2026 22:48:35 +0100 Subject: [PATCH 2/2] t4052: test for diffstat width when prefix contains ANSI escape codes Add test checking the calculation of the diffstat display width when the `line_prefix`, which is text that goes before the diffstat, contains ANSI escape codes. This situation happens, for example, when `git log --stat --graph` is executed: * `--stat` will create a diffstat for each commit * `--graph` will stuff `line_prefix` with the graph portion of the log, which contains ANSI escape codes to color the text Signed-off-by: LorenzoPegorari Signed-off-by: Junio C Hamano --- t/t4052-stat-output.sh | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/t/t4052-stat-output.sh b/t/t4052-stat-output.sh index 740bb97091..7c749062e2 100755 --- a/t/t4052-stat-output.sh +++ b/t/t4052-stat-output.sh @@ -413,4 +413,36 @@ test_expect_success 'merge --stat respects COLUMNS with long name' ' test_cmp expect actual ' +# We want git-log to print only 1 commit containing a single branch graph and a +# diffstat (the diffstat display width, when not manually set through the +# option "--stat-width", will be automatically calculated). +# The diffstat will be only one file, with a placeholder FILENAME, that, with +# enough terminal display width, will contain the following line: +# "| ${FILENAME} | 0" +# where "" and "" are ANSI escape codes to color the text. +# To calculate the minimium terminal display width MIN_TERM_WIDTH so that the +# FILENAME in the diffstat will not be shortened, we take the FILENAME length +# and add 9 to it. +# To check if the diffstat width, when the line_prefix (the "|" of +# the graph) contains ANSI escape codes (the ANSI escape codes to color the +# text), is calculated correctly, we: +# 1. check if it contains the line defined before when using MIN_TERM_WIDTH +# 2. check if it contains the line defined before, but with the FILENAME +# shortened by only one character, when using MIN_TERM_WIDTH - 1 + +test_expect_success 'diffstat where line_prefix contains ANSI escape codes is correct width' ' + FILENAME="placeholder-text-placeholder-text" && + FILENAME_TRIMMED="...eholder-text-placeholder-text" && + MIN_TERM_WIDTH=$((${#FILENAME} + 9)) && + test_config color.diff always && + git commit --allow-empty --allow-empty-message && + >${FILENAME} && + git add ${FILENAME} && + git commit --allow-empty-message && + COLUMNS=$((MIN_TERM_WIDTH)) git log --graph --stat -n1 | test_decode_color >out && + test_grep "| ${FILENAME} | 0" out && + COLUMNS=$((MIN_TERM_WIDTH - 1)) git log --graph --stat -n1 | test_decode_color >out && + test_grep "| ${FILENAME_TRIMMED} | 0" out +' + test_done