Remove global $Indexer, clear index in the testing system instead

_test/core/DokuWikiTest.php

@@ -30,6 +30,8 @@ abstract class DokuWikiTest extends PHPUnit_Framework_TestCase {
 
         // remove any leftovers from the last run
         if(is_dir(DOKU_TMP_DATA)){
+            // clear indexer data and cache
+            idx_get_indexer()->clear();
             TestUtils::rdelete(DOKU_TMP_DATA);
         }
 

inc/indexer.php

@@ -1228,7 +1228,7 @@ class Doku_Indexer {
  * @author Tom N Harris <tnharris@whoopdedo.org>
  */
 function idx_get_indexer() {
-    global $Indexer;
+    static $Indexer;
     if (!isset($Indexer)) {
         $Indexer = new Doku_Indexer();
     }