@matheusbsbs / matheus-bagliano / commits / bccce0f809

blame: fix broken time_buf paddings in relative timestamp

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 <pclouds@gmail.com> Helped-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Jiang Xin <worldhello.net@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jiang Xin committed Apr 21, 2014 at 14:02 UTC bccce0f8099fac6bcc80914726ddf43ca544b3c1

1 file changed +14 -7

builtin/blame.c

+14 -7

@@ -1556,22 +1556,29 @@ static void assign_blame(struct scoreboard *sb, int opt)

1556 static const char *format_time(unsigned long time, const char *tz_str,

1557 int show_raw_time)

1558 {

1559 - static char time_buf[128];

1559 + static struct strbuf time_buf = STRBUF_INIT;

1560

1561 + strbuf_reset(&time_buf);

1562 if (show_raw_time) {

1562 - snprintf(time_buf, sizeof(time_buf), "%lu %s", time, tz_str);

1563 + strbuf_addf(&time_buf, "%lu %s", time, tz_str);

1564 }

1565 else {

1566 const char *time_str;

1566 - int time_len;

1567 + size_t time_width;

1568 int tz;

1569 tz = atoi(tz_str);

1570 time_str = show_date(time, tz, blame_date_mode);

1570 - time_len = strlen(time_str);

1571 - memcpy(time_buf, time_str, time_len);

1572 - memset(time_buf + time_len, ' ', blame_date_width - time_len);

1571 + strbuf_addstr(&time_buf, time_str);

1572 + /*

1573 + * Add space paddings to time_buf to display a fixed width

1574 + * string, and use time_width for display width calibration.

1575 + */

1576 + for (time_width = utf8_strwidth(time_str);

1577 + time_width < blame_date_width;

1578 + time_width++)

1579 + strbuf_addch(&time_buf, ' ');

1580 }

1574 - return time_buf;

1581 + return time_buf.buf;

1582 }

1583

1584 #define OUTPUT_ANNOTATE_COMPAT 001