Get the upgrader to actually work

include/ajax.upgrader.php

@@ -27,13 +27,6 @@ class UpgraderAjaxAPI extends AjaxController {
 
         $upgrader = new Upgrader(TABLE_PREFIX, UPGRADE_DIR.'streams/');
 
-        //Just report the next action on the first call.
-        if(!$_SESSION['ost_upgrader'] || !$_SESSION['ost_upgrader'][$upgrader->getShash()]['progress']) {
-            $_SESSION['ost_upgrader'][$upgrader->getShash()]['progress'] = $upgrader->getNextAction();
-            Http::response(200, $upgrader->getNextAction());
-            exit;
-        }
-
         if($upgrader->isAborted()) {
             Http::response(416, "We have a problem ... wait a sec.");
             exit;

include/class.upgrader.php

@@ -98,7 +98,8 @@ class Upgrader {
     }
 
     function getNumPendingTasks() {
-        return $this->getCurrentStream()->getNumPendingTasks();
+        if ($this->getCurrentStream())
+            return $this->getCurrentStream()->getNumPendingTasks();
     }
 
     function doTasks() {
@@ -125,7 +126,8 @@ class Upgrader {
     }
 
     function getSHash() {
-        return $this->getCurrentStream()->getSHash();
+        if ($this->getCurrentStream())
+            return $this->getCurrentStream()->getSHash();
     }
 }