return ret;
}
+
+void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm)
+{
+ size_t hint = 128;
+ size_t len;
+
+ if (!*fmt)
+ return;
+
+ strbuf_grow(sb, hint);
+ len = strftime(sb->buf + sb->len, sb->alloc - sb->len, fmt, tm);
+
+ if (!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 our strategy is to munge the format so that the
+ * output contains at least one character, and then drop the extra
+ * character before returning.
+ */
+ 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);
+}