notes: fix handling of colon-separated values

The substrings output by strbuf_split() include the ':' delimiters.
When processing GIT_NOTES_DISPLAY_REF and GIT_NOTES_REWRITE_REF, strip
off the delimiter character *before* checking whether the substring is
empty rather than after, so that empty strings within the list are
also skipped.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Acked-by: Johan Herland <johan@herland.net>
Signed-off-by: Jeff King <peff@peff.net>

notes.c

@@ -951,10 +951,10 @@ void string_list_add_refs_from_colon_sep(struct string_list *list,
 	split = strbuf_split(&globbuf, ':');
 
 	for (i = 0; split[i]; i++) {
+		if (split[i]->len && split[i]->buf[split[i]->len-1] == ':')
+			strbuf_setlen(split[i], split[i]->len-1);
 		if (!split[i]->len)
 			continue;
-		if (split[i]->buf[split[i]->len-1] == ':')
-			strbuf_setlen(split[i], split[i]->len-1);
 		string_list_add_refs_by_glob(list, split[i]->buf);
 	}