From 6fc7a1d707023cc180481639c940cf7784f295b8 Mon Sep 17 00:00:00 2001
From: Kevin Israel <pleasestand@live.com>
Date: Mon, 29 Oct 2012 21:49:15 -0400
Subject: [PATCH] Add comments to Linker::formatLinksInComment()

Per Tim Starling's suggestion, added comments to the regex in
Linker::formatLinksInComment().

Change-Id: If85567e5a2e57dd56f5f263f3512e9ed2f9c940c
---
 includes/Linker.php | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/includes/Linker.php b/includes/Linker.php
index 66cb7e7..e711ff5 100644
--- a/includes/Linker.php
+++ b/includes/Linker.php
@@ -1373,7 +1373,18 @@ class Linker {
 		self::$commentContextTitle = $title;
 		self::$commentLocal = $local;
 		$html = preg_replace_callback(
-			'/\[\[:?([^\]|]+)(?:\|((?:]?[^\]|])*+))*\]\]([^[]*)/',
+			'/
+				\[\[
+				:? # ignore optional leading colon
+				([^\]|]+) # 1. link target; page names cannot include ] or |
+				(?:\|
+					# 2. a pipe-separated substring; only the last is captured
+					# Stop matching at | and ]] without relying on backtracking.
+					((?:]?[^\]|])*+)
+				)*
+				\]\]
+				([^[]*) # 3. link trail (the text up until the next link)
+			/x',
 			array( 'Linker', 'formatLinksInCommentCallback' ),
 			$comment );
 		self::$commentContextTitle = null;
-- 
1.8.0