Fix indexable callbacks with alias based indexes

DynamicIndex.php

@@ -11,18 +11,31 @@ use Elastica\Index;
  */
 class DynamicIndex extends Index
 {
+    private $originalName;
+
     /**
      * Reassign index name
      *
-     * While it's technically a regular setter for name property, it's specifically named overrideName, but not setName
-     * since it's used for a very specific case and normally should not be used
+     * While it's technically a regular setter for name property, it's specifically named
+     * overrideName, but not setName since it's used for a very specific case and normally
+     * should not be used.
      *
      * @param string $name Index name
-     *
-     * @return void
      */
     public function overrideName($name)
     {
+        $this->originalName = $this->_name;
         $this->_name = $name;
     }
+
+    /**
+     * Returns the original name of the index if the index has been renamed for reindexing
+     * or realiasing purposes.
+     *
+     * @return string
+     */
+    public function getOriginalName()
+    {
+        return $this->originalName ?: $this->_name;
+    }
 }