From b141546c4e3fe4ea6df7a50406fad8514a4f4e91 Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Thu, 14 Mar 2013 13:23:32 -0700
Subject: [PATCH] Added ScopedCallback functions for early execution or
 cancellation.

Change-Id: I6493cfa81d778c47aa7283dc3196989384235f0a
---
 includes/ScopedCallback.php | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/includes/ScopedCallback.php b/includes/ScopedCallback.php
index 1d5b26bfb7..8ecd87471a 100644
--- a/includes/ScopedCallback.php
+++ b/includes/ScopedCallback.php
@@ -22,6 +22,8 @@
 
 /**
  * Class for asserting that a callback happens when an dummy object leaves scope
+ *
+ * @since 1.21
  */
 class ScopedCallback {
 	/** @var Closure */
@@ -34,7 +36,34 @@ class ScopedCallback {
 		$this->callback = $callback;
 	}
 
+	/**
+	 * Trigger a scoped callback and destroy it.
+	 * This is the same is just setting it to null.
+	 *
+	 * @param ScopedCallback $sc
+	 */
+	public static function consume( ScopedCallback &$sc = null ) {
+		$sc = null;
+	}
+
+	/**
+	 * Destroy a scoped callback without triggering it
+	 *
+	 * @param ScopedCallback $sc
+	 */
+	public static function cancel( ScopedCallback &$sc = null ) {
+		if ( $sc ) {
+			$sc->callback = null;
+		}
+		$sc = null;
+	}
+
+	/**
+	 * Trigger the callback when this leaves scope
+	 */
 	function __destruct() {
-		call_user_func( $this->callback );
+		if ( $this->callback !== null ) {
+			call_user_func( $this->callback );
+		}
 	}
 }
-- 
2.20.1