N°2293 Saves changes in DBObjet::DBUpdate, just before the AfterUpdate call

This will allow to get changes made in ComputeValues, OnUpdate, etc

core/dbobject.class.php

@@ -133,6 +133,11 @@ abstract class DBObject implements iDisplay
 	 *   * false => not modified (the same value as the original value was set)
 	 */
 	protected $m_aModifiedAtt = array();
+	/**
+	 * @var array attname => currentvalue Persists changes for {@link DBUpdate}
+	 * @since 2.7.0 N°2293
+	 */
+	protected $m_aChanges;
 	/**
 	 * @var array Set of Synch data related to this object
 	 * <ul>
@@ -3015,6 +3020,8 @@ abstract class DBObject implements iDisplay
 			throw new CoreException("DBUpdate: could not update a newly created object, please call DBInsert instead");
 		}
 
+		$this->m_aChanges = array(); // reset attribute to avoid stack collisions
+
 		$iNbTryRemaining = 3;
 		while ($iNbTryRemaining > 0)
 		{
@@ -3164,6 +3171,8 @@ abstract class DBObject implements iDisplay
 				$this->DBWriteLinks();
 				$this->WriteExternalAttributes();
 
+				$this->m_aChanges = $this->ListChanges(); // N°2293 save changes for use in user callbacks
+
 				$this->AfterUpdate();
 
 				$this->m_bDirty = false;