ask the database for the low and high ts instead of trying to fudge it

diff --git a/includes/PageHistory.php b/includes/PageHistory.php
index 3329684..06ee5fc 100644 (file)
--- a/includes/PageHistory.php
+++ b/includes/PageHistory.php
@@ -99,7 +99,7 @@ class PageHistory {
                if (($gowhere = $wgRequest->getText("go")) !== NULL) {
                        switch ($gowhere) {
                        case "first":
-                               if (($lastid = $this->getLastOffset($id, $limit)) === NULL)
+                               if (($lastid = $this->getLastOffsetForPaging($id, $limit)) === NULL)
                                        break;
                                $gourl = $wgTitle->getLocalURL("action=history&limit={$limit}&offset={$lastid}");
                                break;
@@ -338,11 +338,27 @@ class PageHistory {
                }
        }
 
-       function getLastOffset($id, $step = 50) {
+       function getFirstOffset($id) {
+               $db =& wfGetDB(DB_SLAVE);
+               $sql = "SELECT MAX(rev_timestamp) AS lowest FROM revision WHERE rev_page = $id";
+               $res = $db->query($sql, "getFirstOffset");
+               $obj = $db->fetchObject($res);
+               return $obj->lowest;
+       }
+
+       function getLastOffset($id) {
+               $db =& wfGetDB(DB_SLAVE);
+               $sql = "SELECT MIN(rev_timestamp) AS lowest FROM revision WHERE rev_page = $id";
+               $res = $db->query($sql, "getLastOffset");
+               $obj = $db->fetchObject($res);
+               return $obj->lowest;
+       }
+
+       function getLastOffsetForPaging($id, $step = 50) {
                $db =& wfGetDB(DB_SLAVE);
                $sql = "SELECT rev_timestamp FROM revision WHERE rev_page = $id " .
                        "ORDER BY rev_timestamp ASC LIMIT $step";
-               $res = $db->query($sql, "getLastOffset");
+               $res = $db->query($sql, "getLastOffsetForPaging");
                $n = $db->numRows($res);
 
                if ($n == 0)
@@ -433,14 +449,11 @@ wfdebug("limits=$limits offset=$offsets got=".count($result)."\n");
        function makeNavbar($revisions, $offset, $limit, $direction) {
                global $wgTitle, $wgLang;
 
-               /*
-                * lowts is the timestamp of the first revision on this page.
-                * hights is the timestamp of the last revision.
-                */
-               $atend = !(count($revisions) > $limit);
-wfDebug("offset=$offset limit=$limit dir=$direction count=".count($revisions)."\n");
                $revisions = array_slice($revisions, 0, $limit);
 
+               $abslowts = $this->getLastOffset($this->mTitle->getArticleID());
+               $abshights = $this->getFirstOffset($this->mTitle->getArticleID());
+
                /*
                 * When we're displaying previous revisions, we need to reverse
                 * the array, because it's queried in reverse order.
@@ -448,6 +461,11 @@ wfDebug("offset=$offset limit=$limit dir=$direction count=".count($revisions)."\
                if ($direction == DIR_PREV)
                        $revisions = array_reverse($revisions);
 
+               /*
+                * lowts is the timestamp of the first revision on this page.
+                * hights is the timestamp of the last revision.
+                */
+
                $lowts = $hights = 0;
 
                if (count($revisions)) {
@@ -468,13 +486,14 @@ wfDebug("offset=$offset limit=$limit dir=$direction count=".count($revisions)."\
                        $urls[] = "<a href=\"".$wgTitle->escapeLocalURL(
                                "action=history&offset={$offset}&limit={$num}")."\">".$wgLang->formatNum($num)."</a>";
                }
+wfDebug("lowts=$lowts abslowts=$abslowts\n");
                $bits = implode($urls, ' | ');
-               if (($direction == DIR_NEXT && $offset) || ($direction == DIR_PREV && !$atend)) {
+               if ($lowts < $abslowts) {
                        $prevtext = "<a href=\"$prevurl\">".wfMsg("prevn", $limit)."</a>";
                        $lasttext = "<a href=\"$lasturl\">$lasttext</a>";
                } else  $prevtext = wfMsg("prevn", $limit);
 
-               if (!$atend || $direction == DIR_PREV) {
+               if ($hights < $abshights) {
                        $nexttext = "<a href=\"$nexturl\">".wfMsg("nextn", $limit)."</a>";
                        $firsttext = "<a href=\"$firsturl\">$firsttext</a>";
                } else  $nexttext = wfMsg("nextn", $limit);