Refs #1334. Prevent cycles in the pages tree.

2 files changed, 23 insertions, 2 deletions

diff --git a/mod/pages/actions/pages/edit.php b/mod/pages/actions/pages/edit.php
index e6387c1a4..bf54ae87d 100644
--- a/mod/pages/actions/pages/edit.php
+++ b/mod/pages/actions/pages/edit.php
@@ -70,7 +70,27 @@ if (sizeof($input) > 0) {
 // need to add check to make sure user can write to container
 $page->container_guid = $container_guid;
 
-if ($parent_guid) {
+if ($parent_guid && $parent_guid != $page_guid) {
+	// Check if parent isn't below of the page in the tree
+	if ($page_guid) {
+		$tree_page = get_entity($parent_guid);
+		while ($tree_page->parent_guid > 0 && $page_guid != $tree_page->guid) {
+			$tree_page = get_entity($tree_page->parent_guid);
+		}
+		// If is below, bring all child elements forward
+		if ($page_guid == $tree_page->guid) {
+			$previous_parent = $page->parent_guid;
+			$children = elgg_get_entities_from_metadata(array(
+				'metadata_name' => 'parent_guid',
+				'metadata_value' => $page->getGUID()
+			));
+			if ($children) {
+				foreach ($children as $child) {
+					$child->parent_guid = $previous_parent;
+				}
+			}
+		}
+	}
 	$page->parent_guid = $parent_guid;
 }
 
diff --git a/mod/pages/views/default/forms/pages/edit.php b/mod/pages/views/default/forms/pages/edit.php
index 119b9ba23..583dc414f 100644
--- a/mod/pages/views/default/forms/pages/edit.php
+++ b/mod/pages/views/default/forms/pages/edit.php
@@ -18,7 +18,8 @@ foreach ($variables as $name => $type) {
 	if (($type == 'access' || $type == 'write_access') && !$can_change_access) {
 		continue;
 	}
-	if ($name == 'parent_guid' && empty($vars['parent_guid'])) {
+	// don't show parent picker input for top or new pages.
+	if ($name == 'parent_guid' && (!$vars['parent_guid'] || !$vars['guid'])) {
 		continue;
 	}
 ?>