From bccce0f8099fac6bcc80914726ddf43ca544b3c1 Mon Sep 17 00:00:00 2001 From: Jiang Xin Date: Mon, 21 Apr 2014 14:02:03 +0800 Subject: [PATCH] blame: fix broken time_buf paddings in relative timestamp MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Command `git blame --date relative` aligns the date field with a fixed-width (defined by blame_date_width), and if time_str is shorter than that, it adds spaces for padding. But there are two bugs in the following codes: time_len = strlen(time_str); ... memset(time_buf + time_len, ' ', blame_date_width - time_len); 1. The type of blame_date_width is size_t, which is unsigned. If time_len is greater than blame_date_width, the result of "blame_date_width - time_len" will never be a negative number, but a really big positive number, and will cause memory overwrite. This bug can be triggered if either l10n message for function show_date_relative() in date.c is longer than 30 characters, then `git blame --date relative` may exit abnormally. 2. When show blame information with relative time, the UTF-8 characters in time_str will break the alignment of columns after the date field. This is because the time_buf padding with spaces should have a constant display width, not a fixed strlen size. So we should call utf8_strwidth() instead of strlen() for width calibration. Helped-by: Nguyễn Thái Ngọc Duy Helped-by: Eric Sunshine Signed-off-by: Jiang Xin Signed-off-by: Junio C Hamano --- builtin/blame.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/builtin/blame.c b/builtin/blame.c index 88cb799727..35e95db15d 100644 --- a/builtin/blame.c +++ b/builtin/blame.c @@ -1556,22 +1556,29 @@ static void assign_blame(struct scoreboard *sb, int opt) static const char *format_time(unsigned long time, const char *tz_str, int show_raw_time) { - static char time_buf[128]; + static struct strbuf time_buf = STRBUF_INIT; + strbuf_reset(&time_buf); if (show_raw_time) { - snprintf(time_buf, sizeof(time_buf), "%lu %s", time, tz_str); + strbuf_addf(&time_buf, "%lu %s", time, tz_str); } else { const char *time_str; - int time_len; + size_t time_width; int tz; tz = atoi(tz_str); time_str = show_date(time, tz, blame_date_mode); - time_len = strlen(time_str); - memcpy(time_buf, time_str, time_len); - memset(time_buf + time_len, ' ', blame_date_width - time_len); + strbuf_addstr(&time_buf, time_str); + /* + * Add space paddings to time_buf to display a fixed width + * string, and use time_width for display width calibration. + */ + for (time_width = utf8_strwidth(time_str); + time_width < blame_date_width; + time_width++) + strbuf_addch(&time_buf, ' '); } - return time_buf; + return time_buf.buf; } #define OUTPUT_ANNOTATE_COMPAT 001 -- 2.11.4.GIT