canon: unbreak qtydiff

diff --git a/yarrg/canon b/yarrg/canon
index e756297e7d525ee880efb0fa7622f8432d87d6ef..590ffa86c0cbd1b203cbeb6c37acb7f6e1a903ca 100755 (executable)
--- a/yarrg/canon
+++ b/yarrg/canon
@@ -69,7 +69,7 @@ foreach my $k (sort keys %s) {
         next;
     }
     # base62-encoding all these numbers saves about 8%
-    my $qtydiff= $r[2] - ($r[0] || 0);
+    my $qtydiff= $r[3] - ($r[1] || 0);
     if (!defined($r[0]) || $r[0] != $r[2]) {
         $prep->();
         printf "\@%s",alencodenum($r[2]);