From: LorenzoPegorari Date: Fri, 16 Jan 2026 00:05:03 +0000 (+0100) Subject: diff: improve scaling of filenames in diffstat to handle UTF-8 chars X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f85b49f3d4af5ee0b428285799ac711d6abe1cfb;p=thirdparty%2Fgit.git diff: improve scaling of filenames in diffstat to handle UTF-8 chars 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. Force `len` to not be less than 0 (this happens if the given `name-width` is 2 or less), otherwise an infinite loop is entered. Signed-off-by: LorenzoPegorari Signed-off-by: Junio C Hamano --- diff --git a/diff.c b/diff.c index a1961526c0..86fdf4d8d7 100644 --- a/diff.c +++ b/diff.c @@ -2823,17 +2823,12 @@ 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; + if (len < 0) + len = 0; + + while (name_len > len) + name_len -= utf8_width((const char**)&name, NULL); + slash = strchr(name, '/'); if (slash) name = slash;