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 <pclo...@gmail.com>
Helped-by: Eric Sunshine <sunsh...@sunshineco.com>
Signed-off-by: Jiang Xin <worldhello....@gmail.com>
---
builtin/blame.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/builtin/blame.c b/builtin/blame.c
index 88cb799..35e95db 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
--
1.9.2.476.ga74def0
--
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
