When `git blame` shows date field in a fixed width (as long as blame_date_width characters), if time_str shorter than that, add spaces for padding. But there are two bugs in the following codes:
memcpy(time_buf, time_str, time_len); memset(time_buf + time_len, ' ', blame_date_width - time_len); 1. The type of blame_date_width is size_t (unsigned int). If time_len is greater than blame_ate_width, "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 then 30 charcters, then `git blame --date relative` may fail. 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 calibration. Signed-off-by: Jiang Xin <worldhello....@gmail.com> --- builtin/blame.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/builtin/blame.c b/builtin/blame.c index 88cb799..0a0a858 100644 --- a/builtin/blame.c +++ b/builtin/blame.c @@ -1556,22 +1556,31 @@ 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; + size_t time_width; int time_len; 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_add(&time_buf, time_str, time_len); + /* + * 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 -- 2.0.0.rc0.3.g444188f.dirty -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html