Reload relevant models after acquiring a lock so that we don't make

database calls based on obsolete data, which can lead to data corruption.

Fixes ticket #926.

1 files changed, 4 insertions, 0 deletions

diff --git a/modules/gallery/libraries/ORM_MPTT.php b/modules/gallery/libraries/ORM_MPTT.php
index 83d2445c..ebd7abc2 100644
--- a/modules/gallery/libraries/ORM_MPTT.php
+++ b/modules/gallery/libraries/ORM_MPTT.php
@@ -48,6 +48,7 @@ class ORM_MPTT_Core extends ORM {
    */
   function add_to_parent($parent) {
     $this->lock();
+    $parent->reload();  // Assume that the prior lock holder may have changed the parent
 
     try {
       // Make a hole in the parent for this new item
@@ -91,6 +92,7 @@ class ORM_MPTT_Core extends ORM {
     }
 
     $this->lock();
+    $this->reload();  // Assume that the prior lock holder may have changed this entry
     try {
       $this->db->query(
         "UPDATE {{$this->table_name}} SET `left_ptr` = `left_ptr` - 2 WHERE `left_ptr` > {$this->right_ptr}");
@@ -224,6 +226,8 @@ class ORM_MPTT_Core extends ORM {
     $level_delta = ($target->level + 1) - $this->level;
 
     $this->lock();
+    $this->reload();  // Assume that the prior lock holder may have changed this entry
+    $target->reload();
     try {
       if ($level_delta) {
         // Update the levels for the to-be-moved items