From 8be3c4bfec39673d73483cfb10e3fd143d5731ff Mon Sep 17 00:00:00 2001
From: Donncha O Caoimh <5656673+donnchawp@users.noreply.github.com>
Date: Tue, 14 Apr 2026 14:52:44 +0100
Subject: [PATCH 1/2] Disable caching for wp_die() error pages

Fixes #1015

Hook wp_die_handler to define DONOTCACHEPAGE when wp_die() is invoked,
preventing error/interstitial pages (e.g. "Error establishing a Redis
connection") from being cached and served to subsequent visitors.

A wpsc_disable_cache_on_wp_die filter preserves the legacy behavior for
sites that intentionally render cacheable content via wp_die().
---
 wp-cache.php | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/wp-cache.php b/wp-cache.php
index 0b3e067d..240941b9 100644
--- a/wp-cache.php
+++ b/wp-cache.php
@@ -157,6 +157,29 @@ function wp_super_cache_init_action() {
 }
 add_action( 'init', 'wp_super_cache_init_action' );
 
+/**
+ * Disable caching for pages rendered via wp_die().
+ *
+ * wp_die() is used to render error and interstitial pages (e.g. "Error
+ * establishing a database connection"); caching them causes the error to
+ * persist for subsequent visitors even after the underlying issue is resolved.
+ *
+ * @param callable $handler The registered wp_die handler, returned unchanged.
+ * @return callable
+ */
+function wpsc_wp_die_disable_cache( $handler ) {
+	/**
+	 * Filters whether to disable caching when wp_die() is invoked.
+	 *
+	 * @param bool $disable Whether to set DONOTCACHEPAGE. Default true.
+	 */
+	if ( apply_filters( 'wpsc_disable_cache_on_wp_die', true ) && ! defined( 'DONOTCACHEPAGE' ) ) {
+		define( 'DONOTCACHEPAGE', true );
+	}
+	return $handler;
+}
+add_filter( 'wp_die_handler', 'wpsc_wp_die_disable_cache' );
+
 function wp_cache_set_home() {
 	global $wp_cache_is_home;
 	$wp_cache_is_home = ( is_front_page() || is_home() );

From ade43e552b6f5bc7721842d1138fe1980f4d3003 Mon Sep 17 00:00:00 2001
From: Donncha O Caoimh <5656673+donnchawp@users.noreply.github.com>
Date: Tue, 14 Apr 2026 15:03:51 +0100
Subject: [PATCH 2/2] Linting warning fix

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

diff --git a/wp-cache.php b/wp-cache.php
index 240941b9..25f01685 100644
--- a/wp-cache.php
+++ b/wp-cache.php
@@ -160,8 +160,8 @@ function wp_super_cache_init_action() {
 /**
  * Disable caching for pages rendered via wp_die().
  *
- * wp_die() is used to render error and interstitial pages (e.g. "Error
- * establishing a database connection"); caching them causes the error to
+ * The function wp_die() is used to render error and interstitial pages (e.g.
+ * "Error establishing a database connection"); caching them causes the error to
  * persist for subsequent visitors even after the underlying issue is resolved.
  *
  * @param callable $handler The registered wp_die handler, returned unchanged.