DDC-868 - Fix bug where a ClassMetadata instance from a STI child level is processed before the parent.

lib/Doctrine/ORM/Tools/SchemaTool.php

@@ -92,6 +92,22 @@ class SchemaTool
         return $schema->toSql($this->_platform);
     }
 
+    /**
+     * Some instances of ClassMetadata don't need to be processed in the SchemaTool context. This method detects them.
+     * 
+     * @param ClassMetadata $class
+     * @param array $processedClasses
+     * @return bool
+     */
+    private function processingNotRequired($class, array $processedClasses)
+    {
+        return (
+            isset($processedClasses[$class->name]) ||
+            $class->isMappedSuperclass ||
+            ($class->isInheritanceTypeSingleTable() && $class->name != $class->rootEntityName)
+        );
+    }
+
     /**
      * From a given set of metadata classes this method creates a Schema instance.
      *
@@ -110,7 +126,7 @@ class SchemaTool
         $evm = $this->_em->getEventManager();
 
         foreach ($classes as $class) {
-            if (isset($processedClasses[$class->name]) || $class->isMappedSuperclass) {
+            if ($this->processingNotRequired($class, $processedClasses)) {
                 continue;
             }