From: LorenzoPegorari Date: Wed, 14 Jan 2026 22:27:18 GMT Subject: [GSoC PATCH 1/1] diff: improve scaling of filenames in diffstat to handle UTF-8 chars Message-ID: The `show_stats()` function tries to scale the filenames in the diffstat to ensure they don't exceed the given `name-width`. It does so by calculating the "display width" of the characters to be dropped, but then advances the filename pointer by that number of bytes. However, the "display width" of a character is not always equal to its byte count. The result is that sometimes, when displaying UTF-8 characters, filenames exceed the given `name-width`, and frequently the bytes of the UTF-8 characters are truncated. The following is an example of the issue, where the 2 files are "HelloHi" and "Hello你好", and `name-width=6`: ...oHi | 0 ...好 | 0 Make the filename pointer move by the actual number of bytes of the characters to drop from the filename, rather than their display width, using the `utf8_width()` function. Signed-off-by: LorenzoPegorari --- diff.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) diff --git a/diff.c b/diff.c index a68ddd2168..271ace5728 100644 --- a/diff.c +++ b/diff.c @@ -2859,17 +2859,10 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options) char *slash; prefix = "..."; len -= 3; - /* - * NEEDSWORK: (name_len - len) counts the display - * width, which would be shorter than the byte - * length of the corresponding substring. - * Advancing "name" by that number of bytes does - * *NOT* skip over that many columns, so it is - * very likely that chomping the pathname at the - * slash we will find starting from "name" will - * leave the resulting string still too long. - */ - name += name_len - len; + + while (name_len > len) + name_len -= utf8_width((const char**)&name, NULL); + slash = strchr(name, '/'); if (slash) name = slash; -- 2.43.0