--- html.php.orig	2007-01-31 16:41:43.000000000 +0100
+++ html.php	2007-01-31 11:49:19.000000000 +0100
@@ -467,11 +467,23 @@
   $date = @date($conf['dformat'],$INFO['lastmod']);
 
   print p_locale_xhtml('revisions');
-  print '<ul>';
+  if ($revisions) {
+    print '<form method="get" action="doku.php">';
+    print '<input type="hidden" name="id" value="'.$ID.'" />';
+    print '<input type="hidden" name="do" value="diff" />';
+    print '<input type="submit" value="Compare selected versions" class="button"/>';
+  }
+  print '<ul>'."\n";
   if($INFO['exists'] && $first==0){
     print (isset($INFO['meta']) && isset($INFO['meta']['last_change']) && $INFO['meta']['last_change']['type']==='e') ? '<li class="minor">' : '<li>';
     print '<div class="li">';
 
+    if ($revisions) {
+      print '<input type="radio" value="" name="rev2" style="visibility:hidden"/>';
+      print '<input type="radio" value="" name="rev" checked="checked"/>';
+    }
+
+
     print $date;
 
     print ' <img src="'.DOKU_BASE.'lib/images/blank.gif" width="15" height="11" alt="" /> ';
@@ -489,12 +501,31 @@
     print '</li>';
   }
 
+  $checked = false;
+
   foreach($revisions as $rev){
     $date = date($conf['dformat'],$rev);
     $info = getRevisionInfo($ID,$rev,true);
 
     print ($info['type']==='e') ? '<li class="minor">' : '<li>';
     print '<div class="li">';
+
+    if(@file_exists(wikiFN($ID,$rev))){
+        if( !$checked ){
+            print '<input type="radio" name="rev2" checked="checked" value="'.$rev.'"/>';
+            $checked = true;
+        }
+        else{
+            print '<input type="radio" name="rev2" value="'.$rev.'"/>';
+        }
+        print '<input type="radio" name="rev" value="'.$rev.'"/>';
+    }
+    else{
+      print '<input type="radio" value="" name="rev2" style="visibility:hidden"/>';
+      print '<input type="radio" value="" name="rev" style="visibility:hidden"/>';
+    }
+
+
     print $date;
 
     if(@file_exists(wikiFN($ID,$rev))){
@@ -526,10 +557,15 @@
     print '</span>';
 
     print '</div>';
-    print '</li>';
+    print '</li>'."\n";
   }
   print '</ul>';
 
+  if ($revisions) {
+    print '<input type="submit" value="Compare selected versions" class="button"/>';
+    print '</form>';
+  }
+
   print '<div class="pagenav">';
   $last = $first + $conf['recent'];
   if ($first > 0) {
@@ -812,17 +848,53 @@
   require_once(DOKU_INC.'inc/DifferenceEngine.php');
   global $ID;
   global $REV;
+  global $REV2;
   global $lang;
   global $conf;
 
-  if($text){
+  // get the filetime of the current revision
+  // might use this for allowing the RSS feed to show diffs of current to old
+  $filetime = filemtime(wikiFN($ID));
+
+  if( $REV == $filetime ){
+    //print 'Filetime matched, using current<br>';
+    $REV = '';
+  }
+
+  if( $REV2 == $filetime ){
+    //print 'Filetime matched, using current<br>';
+    $REV2 = '';
+  }
+
+  if($text){ // diff for conflicts
     $df  = new Diff(explode("\n",htmlspecialchars(rawWiki($ID,''))),
                     explode("\n",htmlspecialchars(cleanText($text))));
     $left  = '<a class="wikilink1" href="'.wl($ID).'">'.
               $ID.' '.date($conf['dformat'],@filemtime(wikiFN($ID))).'</a>'.
               $lang['current'];
     $right = $lang['yours'];
-  }else{
+  }elseif($REV && $REV2){ // diff between versions
+    $df  = new Diff(explode("\n",htmlspecialchars(rawWiki($ID,$REV2))),
+                    explode("\n",htmlspecialchars(rawWiki($ID,$REV))));
+
+    $left  = '<a class="wikilink1" href="'.wl($ID,"rev=$REV2").'">'.
+              $ID.' '.date($conf['dformat'],$REV2).'</a>';
+
+    $right = '<a class="wikilink1" href="'.wl($ID,"rev=$REV").'">'.
+              $ID.' '.date($conf['dformat'],$REV).'</a>';
+
+  }elseif($REV2){ // diff between current and REV2
+    $df  = new Diff(explode("\n",htmlspecialchars(rawWiki($ID,$REV2))),
+                    explode("\n",htmlspecialchars(rawWiki($ID,$REV))));
+
+    $left = '<a class="wikilink1" href="'.wl($ID,"rev=$REV2").'">'.
+              $ID.' '.date($conf['dformat'],$REV2).'</a>';
+
+    $right  = '<a class="wikilink1" href="'.wl($ID).'">'.
+              $ID.' '.date($conf['dformat'],@filemtime(wikiFN($ID))).'</a> '.
+              $lang['current'];
+
+  }else{ 
     if($REV){
       $r = $REV;
     }else{
@@ -846,6 +918,7 @@
               $ID.' '.date($conf['dformat'],@filemtime(wikiFN($ID))).'</a> '.
               $lang['current'];
   }
+
   $tdf = new TableDiffFormatter();
   if($intro) print p_locale_xhtml('diff');
   ?>