back button tear down walls

The 'back' currently works only inside a namespace and hide the
button, if the namespace startpage has been reached.

This patch tear down the namespace wall. Now the 'back' button
of the namespace startpage addresses the start page of the
parent namespace instead of being hidden.

With this patch the 'back' button works as before the 'startpage'
patch series.

darcs-hash:20060619171023-7ef76-baac3ad5367d6c6397125401aa7d8beab5122faa.gz

inc/template.php

@@ -259,7 +259,12 @@ function tpl_getparent($id){
   global $conf;
   $parent = getNS($id).':';
   resolve_pageid('',$parent,$exists);
-  if($parent == $id) return false;
+  if($parent == $id) {
+    $pos = strrpos (getNS($id),':');
+    $parent = substr($parent,0,$pos).':';
+    resolve_pageid('',$parent,$exists);
+    if($parent == $id) return false;
+  }
   return $parent;
 }