From 18753eb0c6c85b3e0dc81a6266226563aa1c62a2 Mon Sep 17 00:00:00 2001
From: Jake Morrison <68693+jom@users.noreply.github.com>
Date: Tue, 7 Apr 2026 16:36:46 -0500
Subject: [PATCH 1/4] fix: hide debug HTML comments in REST and Ajax responses

---
 wp-cache-phase2.php | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/wp-cache-phase2.php b/wp-cache-phase2.php
index d3c5ce3d..5ff03953 100644
--- a/wp-cache-phase2.php
+++ b/wp-cache-phase2.php
@@ -2210,7 +2210,14 @@ function wp_cache_append_tag( &$buffer ) {
 		$msg = "Live page served on $timestamp";
 	}
 
-	if ( strpos( $buffer, '<html' ) === false ) {
+	// Don't output debug message if we aren't handling a normal HTML response.
+	if (
+		strpos( $buffer, '<html' ) === false ||
+		( defined( 'REST_REQUEST' ) && REST_REQUEST ) ||
+		( defined( 'JSON_REQUEST' ) && JSON_REQUEST ) ||
+		( defined( 'WC_API_REQUEST' ) && WC_API_REQUEST ) ||
+		( function_exists( 'wp_doing_ajax' ) && wp_doing_ajax() )
+	) {
 		wp_cache_debug( site_url( $_SERVER['REQUEST_URI'] ) . ' - ' . $msg );
 		return false;
 	}
@@ -2229,7 +2236,14 @@ function wp_cache_add_to_buffer( &$buffer, $text ) {
 		return false;
 	}
 
-	if ( strpos( $buffer, '<html' ) === false ) {
+	// Don't output debug message if we aren't handling a normal HTML response.
+	if (
+		strpos( $buffer, '<html' ) === false ||
+		( defined( 'REST_REQUEST' ) && REST_REQUEST ) ||
+		( defined( 'JSON_REQUEST' ) && JSON_REQUEST ) ||
+		( defined( 'WC_API_REQUEST' ) && WC_API_REQUEST ) ||
+		( function_exists( 'wp_doing_ajax' ) && wp_doing_ajax() )
+	) {
 		wp_cache_debug( site_url( $_SERVER['REQUEST_URI'] ) . ' - ' . $text );
 		return false;
 	}

From b86fa97fe937a2eeb279da03d0ab904a12e96a7d Mon Sep 17 00:00:00 2001
From: Brandon Kraft <public@brandonkraft.com>
Date: Tue, 7 Apr 2026 17:24:36 -0500
Subject: [PATCH 2/4] fix: clarify debug comment suppression messages

---
 wp-cache-phase2.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/wp-cache-phase2.php b/wp-cache-phase2.php
index 5ff03953..dc58b271 100644
--- a/wp-cache-phase2.php
+++ b/wp-cache-phase2.php
@@ -2210,7 +2210,7 @@ function wp_cache_append_tag( &$buffer ) {
 		$msg = "Live page served on $timestamp";
 	}
 
-	// Don't output debug message if we aren't handling a normal HTML response.
+	// Don't append debug HTML comments to non-HTML responses (REST, Ajax, etc.).
 	if (
 		strpos( $buffer, '<html' ) === false ||
 		( defined( 'REST_REQUEST' ) && REST_REQUEST ) ||
@@ -2236,7 +2236,7 @@ function wp_cache_add_to_buffer( &$buffer, $text ) {
 		return false;
 	}
 
-	// Don't output debug message if we aren't handling a normal HTML response.
+	// Don't append debug HTML comments to non-HTML responses (REST, Ajax, etc.).
 	if (
 		strpos( $buffer, '<html' ) === false ||
 		( defined( 'REST_REQUEST' ) && REST_REQUEST ) ||

From 2ac3825d2e13fbfcb9af03cba15c4415502a219f Mon Sep 17 00:00:00 2001
From: Donncha O Caoimh <5656673+donnchawp@users.noreply.github.com>
Date: Wed, 27 May 2026 17:25:44 +0100
Subject: [PATCH 3/4] Extract wpsc_skip_debug_output() to de-duplicate the
 non-HTML response check

The REST/Ajax/JSON/WC bail condition was copy-pasted into both wp_cache_append_tag() and wp_cache_add_to_buffer(). Move it into a single named predicate so the two call sites can't drift, and drop the explanatory comment the inline condition needed.
---
 wp-cache-phase2.php | 26 ++++++++++----------------
 1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/wp-cache-phase2.php b/wp-cache-phase2.php
index dc58b271..5c6fa0b3 100644
--- a/wp-cache-phase2.php
+++ b/wp-cache-phase2.php
@@ -2191,6 +2191,14 @@ function wp_cache_ob_callback( $buffer ) {
 	}
 }
 
+function wpsc_skip_debug_output( $buffer ) {
+	return strpos( $buffer, '<html' ) === false ||
+		( defined( 'REST_REQUEST' ) && REST_REQUEST ) ||
+		( defined( 'JSON_REQUEST' ) && JSON_REQUEST ) ||
+		( defined( 'WC_API_REQUEST' ) && WC_API_REQUEST ) ||
+		( function_exists( 'wp_doing_ajax' ) && wp_doing_ajax() );
+}
+
 function wp_cache_append_tag( &$buffer ) {
 	global $wp_cache_gmt_offset, $wp_super_cache_comments;
 	global $cache_enabled, $super_cache_enabled;
@@ -2210,14 +2218,7 @@ function wp_cache_append_tag( &$buffer ) {
 		$msg = "Live page served on $timestamp";
 	}
 
-	// Don't append debug HTML comments to non-HTML responses (REST, Ajax, etc.).
-	if (
-		strpos( $buffer, '<html' ) === false ||
-		( defined( 'REST_REQUEST' ) && REST_REQUEST ) ||
-		( defined( 'JSON_REQUEST' ) && JSON_REQUEST ) ||
-		( defined( 'WC_API_REQUEST' ) && WC_API_REQUEST ) ||
-		( function_exists( 'wp_doing_ajax' ) && wp_doing_ajax() )
-	) {
+	if ( wpsc_skip_debug_output( $buffer ) ) {
 		wp_cache_debug( site_url( $_SERVER['REQUEST_URI'] ) . ' - ' . $msg );
 		return false;
 	}
@@ -2236,14 +2237,7 @@ function wp_cache_add_to_buffer( &$buffer, $text ) {
 		return false;
 	}
 
-	// Don't append debug HTML comments to non-HTML responses (REST, Ajax, etc.).
-	if (
-		strpos( $buffer, '<html' ) === false ||
-		( defined( 'REST_REQUEST' ) && REST_REQUEST ) ||
-		( defined( 'JSON_REQUEST' ) && JSON_REQUEST ) ||
-		( defined( 'WC_API_REQUEST' ) && WC_API_REQUEST ) ||
-		( function_exists( 'wp_doing_ajax' ) && wp_doing_ajax() )
-	) {
+	if ( wpsc_skip_debug_output( $buffer ) ) {
 		wp_cache_debug( site_url( $_SERVER['REQUEST_URI'] ) . ' - ' . $text );
 		return false;
 	}

From 737ffb9ddf02b28f1536bef7dc420d76315e3a7e Mon Sep 17 00:00:00 2001
From: Donncha O Caoimh <5656673+donnchawp@users.noreply.github.com>
Date: Wed, 27 May 2026 17:31:28 +0100
Subject: [PATCH 4/4] Also skip debug comments on XML-RPC requests

advanced-cache.php already treats XMLRPC_REQUEST as a non-HTML response type; keep wpsc_skip_debug_output() consistent so XML-RPC bodies stay clean regardless of the <html sniff.
---
 wp-cache-phase2.php | 1 +
 1 file changed, 1 insertion(+)

diff --git a/wp-cache-phase2.php b/wp-cache-phase2.php
index 5c6fa0b3..9a164b28 100644
--- a/wp-cache-phase2.php
+++ b/wp-cache-phase2.php
@@ -2196,6 +2196,7 @@ function wpsc_skip_debug_output( $buffer ) {
 		( defined( 'REST_REQUEST' ) && REST_REQUEST ) ||
 		( defined( 'JSON_REQUEST' ) && JSON_REQUEST ) ||
 		( defined( 'WC_API_REQUEST' ) && WC_API_REQUEST ) ||
+		( defined( 'XMLRPC_REQUEST' ) && XMLRPC_REQUEST ) ||
 		( function_exists( 'wp_doing_ajax' ) && wp_doing_ajax() );
 }