diff options
Diffstat (limited to 'strbuf.c')
| -rw-r--r-- | strbuf.c | 38 |
1 files changed, 21 insertions, 17 deletions
@@ -712,29 +712,33 @@ char *xstrfmt(const char *fmt, ...) void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm) { + size_t hint = 128; size_t len; - /* - * strftime reports "0" if it could not fit the result in the buffer. - * Unfortunately, it also reports "0" if the requested time string - * takes 0 bytes. So if we were to probe and grow, we have to choose - * some arbitrary cap beyond which we guess that the format probably - * just results in a 0-length output. Since we have to choose some - * reasonable cap anyway, and since it is not that big, we may - * as well just grow to their in the first place. - */ - strbuf_grow(sb, 128); + if (!*fmt) + return; + + strbuf_grow(sb, hint); len = strftime(sb->buf + sb->len, sb->alloc - sb->len, fmt, tm); if (!len) { /* - * Either we failed, or the format actually produces a 0-length - * output. There's not much we can do, so we leave it blank. - * However, the output array is left in an undefined state, so - * we must re-assert our NUL terminator. + * strftime reports "0" if it could not fit the result in the buffer. + * Unfortunately, it also reports "0" if the requested time string + * takes 0 bytes. So our strategy is to munge the format so that the + * output contains at least one character, and then drop the extra + * character before returning. */ - sb->buf[sb->len] = '\0'; - } else { - sb->len += len; + struct strbuf munged_fmt = STRBUF_INIT; + strbuf_addf(&munged_fmt, "%s ", fmt); + while (!len) { + hint *= 2; + strbuf_grow(sb, hint); + len = strftime(sb->buf + sb->len, sb->alloc - sb->len, + munged_fmt.buf, tm); + } + strbuf_release(&munged_fmt); + len--; /* drop munged space */ } + strbuf_setlen(sb, sb->len + len); } |