From fcffad860da402f0790f36b14c5661b755f141ff Mon Sep 17 00:00:00 2001
From: ramon <ramonjd@gmail.com>
Date: Tue, 18 Jul 2023 10:29:27 +1000
Subject: [PATCH] Backporting core changes from
 https://github.com/WordPress/wordpress-develop/pull/4845

---
 lib/compat/wordpress-6.3/footnotes.php | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/lib/compat/wordpress-6.3/footnotes.php b/lib/compat/wordpress-6.3/footnotes.php
index 45f4c74b05e37..6225b280e1b6c 100644
--- a/lib/compat/wordpress-6.3/footnotes.php
+++ b/lib/compat/wordpress-6.3/footnotes.php
@@ -18,8 +18,15 @@ function gutenberg_trim_footnotes( $content ) {
 		return $content;
 	}
 
-	static $footnote_pattern = '_<sup data-fn="[^"]+" class="[^"]+">\s*<a href="[^"]+" id="[^"]+">\d+</a>\s*</sup>_';
-	return preg_replace( $footnote_pattern, '', $content );
+	if ( ! str_contains( $content, 'data-fn=' ) ) {
+		return $content;
+	}
+
+	return preg_replace(
+		'_<sup data-fn="[^"]+" class="[^"]+">\s*<a href="[^"]+" id="[^"]+">\d+</a>\s*</sup>_',
+		'',
+		$content
+	);
 }
 
 add_filter( 'the_content', 'gutenberg_trim_footnotes' );