From 0ebc6863e379e2816e46e3121ddcd623d6298526 Mon Sep 17 00:00:00 2001
From: Sukhendu Sekhar Guria <sukhendu.guria@rtcamp.com>
Date: Wed, 3 Jun 2026 13:36:05 +0530
Subject: [PATCH 1/2] Fix add_option duplicate key behavior

---
 src/wp-includes/option.php            | 11 ++++++++-
 tests/phpunit/tests/option/option.php | 32 +++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/src/wp-includes/option.php b/src/wp-includes/option.php
index 7979c119a986f..e280da313b772 100644
--- a/src/wp-includes/option.php
+++ b/src/wp-includes/option.php
@@ -1137,8 +1137,17 @@ function add_option( $option, $value = '', $deprecated = '', $autoload = null )
 	 */
 	do_action( 'add_option', $option, $value );
 
-	$result = $wpdb->query( $wpdb->prepare( "INSERT INTO `$wpdb->options` (`option_name`, `option_value`, `autoload`) VALUES (%s, %s, %s) ON DUPLICATE KEY UPDATE `option_name` = VALUES(`option_name`), `option_value` = VALUES(`option_value`), `autoload` = VALUES(`autoload`)", $option, $serialized_value, $autoload ) );
+	$result = $wpdb->query( $wpdb->prepare( "INSERT INTO `$wpdb->options` (`option_name`, `option_value`, `autoload`) VALUES (%s, %s, %s) ON DUPLICATE KEY UPDATE `option_name` = `option_name`", $option, $serialized_value, $autoload ) );
 	if ( ! $result ) {
+		if ( 0 === $result && ! wp_installing() ) {
+			$notoptions = wp_cache_get( 'notoptions', 'options' );
+
+			if ( is_array( $notoptions ) && isset( $notoptions[ $option ] ) ) {
+				unset( $notoptions[ $option ] );
+				wp_cache_set( 'notoptions', $notoptions, 'options' );
+			}
+		}
+
 		return false;
 	}
 
diff --git a/tests/phpunit/tests/option/option.php b/tests/phpunit/tests/option/option.php
index 53cc5e75f4d31..6ff99566366a1 100644
--- a/tests/phpunit/tests/option/option.php
+++ b/tests/phpunit/tests/option/option.php
@@ -40,6 +40,38 @@ public function test_the_basics() {
 		$this->assertFalse( get_option( $key2 ) );
 	}
 
+	/**
+	 * @ticket 51486
+	 *
+	 * @covers ::add_option
+	 */
+	public function test_add_option_should_not_update_existing_option_when_notoptions_cache_is_stale() {
+		global $wpdb;
+
+		$option = 'ticket_51486';
+
+		$this->assertTrue( add_option( $option, 'original', '', false ) );
+
+		$notoptions            = wp_cache_get( 'notoptions', 'options' );
+		$notoptions            = is_array( $notoptions ) ? $notoptions : array();
+		$notoptions[ $option ] = true;
+		wp_cache_set( 'notoptions', $notoptions, 'options' );
+
+		$this->assertFalse( add_option( $option, 'changed', '', true ) );
+
+		$row = $wpdb->get_row( $wpdb->prepare( "SELECT option_value, autoload FROM $wpdb->options WHERE option_name = %s", $option ) );
+
+		$this->assertSame( 'original', $row->option_value );
+		$this->assertSame( 'off', $row->autoload );
+
+		wp_cache_delete( $option, 'options' );
+		$this->assertSame( 'original', get_option( $option ) );
+
+		$notoptions = wp_cache_get( 'notoptions', 'options' );
+		$this->assertIsArray( $notoptions );
+		$this->assertArrayNotHasKey( $option, $notoptions );
+	}
+
 	/**
 	 * @covers ::get_option
 	 * @covers ::add_option

From 72ae859a439e56dbff30ded31159a28f98c4932f Mon Sep 17 00:00:00 2001
From: Sukhendu Sekhar Guria <sukhendu.guria@rtcamp.com>
Date: Wed, 3 Jun 2026 14:44:49 +0530
Subject: [PATCH 2/2] Fix update_option() fallback for false values

---
 src/wp-includes/option.php | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/wp-includes/option.php b/src/wp-includes/option.php
index e280da313b772..79be58243ae27 100644
--- a/src/wp-includes/option.php
+++ b/src/wp-includes/option.php
@@ -924,7 +924,13 @@ function update_option( $option, $value, $autoload = null ) {
 
 	/** This filter is documented in wp-includes/option.php */
 	if ( apply_filters( "default_option_{$option}", false, $option, false ) === $old_value ) {
-		return add_option( $option, $value, '', $autoload );
+		if ( add_option( $option, $value, '', $autoload ) ) {
+			return true;
+		}
+
+		if ( ! $wpdb->get_var( $wpdb->prepare( "SELECT option_id FROM $wpdb->options WHERE option_name = %s LIMIT 1", $option ) ) ) {
+			return false;
+		}
 	}
 
 	$serialized_value = maybe_serialize( $value );