diff --git a/src/wp-admin/includes/class-wp-site-health.php b/src/wp-admin/includes/class-wp-site-health.php
index 44c04175abaf2..2beff559ff621 100644
--- a/src/wp-admin/includes/class-wp-site-health.php
+++ b/src/wp-admin/includes/class-wp-site-health.php
@@ -2800,10 +2800,19 @@ public function get_test_search_engine_visibility() {
 	 */
 	public function get_test_opcode_cache(): array {
 		$opcode_cache_enabled = false;
-		if ( function_exists( 'opcache_get_status' ) ) {
-			$status = @opcache_get_status( false ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- Warning emitted in failure case.
-			if ( $status && true === $status['opcache_enabled'] ) {
+		if ( extension_loaded( 'Zend OPcache' ) ) {
+			$enabled = ini_get( 'opcache.enable' );
+
+			if ( $enabled ) {
 				$opcode_cache_enabled = true;
+
+				// Only try to read status if it actually works.
+				if ( function_exists( 'opcache_get_status' ) ) {
+					$status = @opcache_get_status( false );
+					if ( is_array( $status ) && isset( $status['opcache_enabled'] ) ) {
+						$opcode_cache_enabled = (bool) $status['opcache_enabled'];
+					}
+				}
 			}
 		}
 
diff --git a/src/wp-admin/install.php b/src/wp-admin/install.php
index b655af53f0cb6..864f65b5ee104 100644
--- a/src/wp-admin/install.php
+++ b/src/wp-admin/install.php
@@ -218,7 +218,7 @@ function display_setup_form( $error = null ) {
 	die(
 		'<h1>' . __( 'Already Installed' ) . '</h1>' .
 		'<p>' . __( 'You appear to have already installed WordPress. To reinstall please clear your old database tables first.' ) . '</p>' .
-		'<p class="step"><a href="' . esc_url( wp_login_url() ) . '">' . __( 'Log In' ) . '</a></p>' .
+		'<p class="step"><a class="button button-primary" href="' . esc_url( wp_login_url() ) . '">' . __( 'Log In' ) . '</a></p>' .
 		'</body></html>'
 	);
 }
@@ -462,7 +462,7 @@ function display_setup_form( $error = null ) {
 	</tr>
 </table>
 
-<p class="step"><a href="<?php echo esc_url( wp_login_url() ); ?>"><?php _e( 'Log In' ); ?></a></p>
+<p class="step"><a class="button button-primary" href="<?php echo esc_url( wp_login_url() ); ?>"><?php _e( 'Log In' ); ?></a></p>
 
 			<?php
 		}
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
index 8e343d2447141..3a529f8201dea 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
@@ -966,7 +966,11 @@ public function update_item( $request ) {
 		 * To ensure that a unique slug is generated, pass the post data with the 'publish' status.
 		 */
 		if ( ! empty( $post->post_name ) && in_array( $post_status, array( 'draft', 'pending' ), true ) ) {
-			$post_parent     = ! empty( $post->post_parent ) ? $post->post_parent : 0;
+			if ( ! empty( $post->post_parent ) ) {
+				$post_parent = (int) $post->post_parent;
+			} else {
+				$post_parent = ! empty( $post_before->post_parent ) ? (int) $post_before->post_parent : 0;
+			}
 			$post->post_name = wp_unique_post_slug(
 				$post->post_name,
 				$post->ID,