diff -r 000000000000 -r 7f95f8617b0b vendor/doctrine/lib/Doctrine/ORM/Internal/CommitOrderCalculator.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/vendor/doctrine/lib/Doctrine/ORM/Internal/CommitOrderCalculator.php	Sat Sep 24 15:40:41 2011 +0200
@@ -0,0 +1,118 @@
+<?php
+/*
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the LGPL. For more information, see
+ * <http://www.doctrine-project.org>.
+ */
+
+namespace Doctrine\ORM\Internal;
+
+/**
+ * The CommitOrderCalculator is used by the UnitOfWork to sort out the
+ * correct order in which changes to entities need to be persisted.
+ *
+ * @since 2.0
+ * @author Roman Borschel <roman@code-factory.org> 
+ */
+class CommitOrderCalculator
+{
+    const NOT_VISITED = 1;
+    const IN_PROGRESS = 2;
+    const VISITED = 3;
+    
+    private $_nodeStates = array();
+    private $_classes = array(); // The nodes to sort
+    private $_relatedClasses = array();
+    private $_sorted = array();
+    
+    /**
+     * Clears the current graph.
+     *
+     * @return void
+     */
+    public function clear()
+    {
+        $this->_classes =
+        $this->_relatedClasses = array();
+    }
+    
+    /**
+     * Gets a valid commit order for all current nodes.
+     * 
+     * Uses a depth-first search (DFS) to traverse the graph.
+     * The desired topological sorting is the reverse postorder of these searches.
+     *
+     * @return array The list of ordered classes.
+     */
+    public function getCommitOrder()
+    {
+        // Check whether we need to do anything. 0 or 1 node is easy.
+        $nodeCount = count($this->_classes);
+        if ($nodeCount == 0) {
+            return array();
+        } else if ($nodeCount == 1) {
+            return array_values($this->_classes);
+        }
+        
+        // Init
+        foreach ($this->_classes as $node) {
+            $this->_nodeStates[$node->name] = self::NOT_VISITED;
+        }
+        
+        // Go
+        foreach ($this->_classes as $node) {
+            if ($this->_nodeStates[$node->name] == self::NOT_VISITED) {
+                $this->_visitNode($node);
+            }
+        }
+
+        $sorted = array_reverse($this->_sorted);
+
+        $this->_sorted = $this->_nodeStates = array();
+
+        return $sorted;
+    }
+
+    private function _visitNode($node)
+    {
+        $this->_nodeStates[$node->name] = self::IN_PROGRESS;
+
+        if (isset($this->_relatedClasses[$node->name])) {
+            foreach ($this->_relatedClasses[$node->name] as $relatedNode) {
+                if ($this->_nodeStates[$relatedNode->name] == self::NOT_VISITED) {
+                    $this->_visitNode($relatedNode);
+                }
+            }
+        }
+
+        $this->_nodeStates[$node->name] = self::VISITED;
+        $this->_sorted[] = $node;
+    }
+    
+    public function addDependency($fromClass, $toClass)
+    {
+        $this->_relatedClasses[$fromClass->name][] = $toClass;
+    }
+    
+    public function hasClass($className)
+    {
+        return isset($this->_classes[$className]);
+    }
+    
+    public function addClass($class)
+    {
+        $this->_classes[$class->name] = $class;
+    }
+}
\ No newline at end of file