use rev1, rev2
http://wintersunset.delfi.lan/dokuwiki/googledrawing?do=diff&rev1=1345291381&rev2=&difftype=sidebyside
---- dokuwiki-2012-07-16/inc/html.php~ 2012-07-16 11:47:58.000000000 +0300
-+++ dokuwiki-2012-07-16/inc/html.php 2012-07-16 11:53:24.640163788 +0300
-@@ -1086,9 +1086,13 @@
- // given as rev and rev2 parameters, with rev2 being optional. Or in an
- // array in rev2.
+--- dokuwiki-2014-05-06/inc/html.php 2014-05-08 11:27:02.548232655 +0300
++++ dokuwiki-2014-05-06/inc/html.php 2014-05-08 11:27:02.548232655 +0300
+@@ -1134,7 +1134,13 @@
$rev1 = $REV;
--
+
$rev2 = $INPUT->ref('rev2');
-- if(is_array($rev2)){
+- if(is_array($rev2)) {
+
+ // handle $r1 + $r2, see DW #1821
+ if ($INPUT->has('r1') && $INPUT->has('r2')) {
+ $rev1 = $INPUT->int('r1');
+ $rev2 = $INPUT->int('r2');
++
+ } elseif(is_array($rev2)){
$rev1 = (int) $rev2[0];
$rev2 = (int) $rev2[1];
---- dokuwiki-20110329/inc/html.php~ 2011-03-29 09:20:42.000000000 +0300
-+++ dokuwiki-20110329/inc/html.php 2011-03-29 09:21:51.507042136 +0300
-@@ -1030,8 +1030,8 @@
-
- $diffurl = wl($ID, array(
- 'do' => 'diff',
-- 'rev2[0]' => $l_rev,
-- 'rev2[1]' => $r_rev,
-+ 'r1' => $l_rev,
-+ 'r2' => $r_rev,
- 'difftype' => $type,
- ));
- ptln('<br /><a class="wikilink1" href="'.$diffurl.'">'.$lang['difflink'].'</a>');
+@@ -1458,8 +1464,8 @@
+ } else {
+ $urlparam = array(
+ 'do' => 'diff',
+- 'rev2[0]' => $lrev,
+- 'rev2[1]' => $rrev,
++ 'r1' => $lrev,
++ 'r2' => $rrev,
+ 'difftype' => $difftype,
+ );
+ }
--- dokuwiki/inc/subscription.php 2013-05-29 22:02:46.801329978 +0300
+++ dokuwiki/inc/subscription.php 2013-05-29 23:04:29.374883349 +0300
@@ -384,12 +384,13 @@