From f744eb816149926939470e679a7e4d86c863a8b3 Mon Sep 17 00:00:00 2001
From: Peter Dias <peter@moodle.com>
Date: Wed, 13 Jan 2021 10:20:15 +0800
Subject: [PATCH] MDL-71702 core: Add custom Moodle patch to minify

There is a Pull-request from Tim Hunt to the project in GitHub
(https://github.com/matthiasmullie/minify/issues/317) but, for now,
as it hasn't been applied yet, we need to manually cherry-pick
this change.
---
 lib/minify/matthiasmullie-minify/src/CSS.php | 28 ++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/lib/minify/matthiasmullie-minify/src/CSS.php b/lib/minify/matthiasmullie-minify/src/CSS.php
index eb98e52ed38..f50d96bbf47 100644
--- a/lib/minify/matthiasmullie-minify/src/CSS.php
+++ b/lib/minify/matthiasmullie-minify/src/CSS.php
@@ -637,7 +637,35 @@ class CSS extends Minify
 
             return $placeholder;
         };
+        // Moodle-specific change MDL-68191 starts.
+        /* This was the old code:
         $this->registerPattern('/\n?\/\*(!|.*?@license|.*?@preserve).*?\*\/\n?/s', $callback);
+        */
+        // This is the new, more accurate and faster regex.
+        $this->registerPattern('/
+            # optional newline
+            \n?
+
+            # start comment
+            \/\*
+
+            # comment content
+            (?:
+                # either starts with an !
+                !
+            |
+                # or, after some number of characters which do not end the comment
+                (?:(?!\*\/).)*?
+
+                # there is either a @license or @preserve tag
+                @(?:license|preserve)
+            )
+
+            # then match to the end of the comment
+            .*?\*\/\n?
+
+            /ixs', $callback);
+        // Moodle-specific change MDL-68191.
 
         $this->registerPattern('/\/\*.*?\*\//s', '');
     }