Customize: Keep alive auto-drafts created for page/post stubs when parent changeset is updated, and delete when changeset is garbage-collected.

Props utkarshpatel, westonruter.
See #31089.
Fixes #39715.

Built from https://develop.svn.wordpress.org/trunk@40676


git-svn-id: http://core.svn.wordpress.org/trunk@40539 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/default-filters.php

@@ -325,6 +325,7 @@ add_action( 'welcome_panel',              'wp_welcome_panel'
 add_action( 'delete_post',                '_wp_delete_post_menu_item'         );
 add_action( 'delete_term',                '_wp_delete_tax_menu_item',   10, 3 );
 add_action( 'transition_post_status',     '_wp_auto_add_pages_to_menu', 10, 3 );
+add_action( 'delete_post',                '_wp_delete_customize_changeset_dependent_auto_drafts' );
 
 // Post Thumbnail CSS class filtering
 add_action( 'begin_fetch_post_thumbnail_html', '_wp_post_thumbnail_class_filter_add'    );
@@ -400,6 +401,7 @@ add_action( 'plugins_loaded', '_wp_customize_include' );
 add_action( 'transition_post_status', '_wp_customize_publish_changeset', 10, 3 );
 add_action( 'admin_enqueue_scripts', '_wp_customize_loader_settings' );
 add_action( 'delete_attachment', '_delete_attachment_theme_mod' );
+add_action( 'transition_post_status', '_wp_keep_alive_customize_changeset_dependent_auto_drafts', 20, 3 );
 
 // Calendar widget cache
 add_action( 'save_post', 'delete_get_calendar_cache' );

wp-includes/nav-menu.php

@@ -978,3 +978,31 @@ function _wp_auto_add_pages_to_menu( $new_status, $old_status, $post ) {
 		wp_update_nav_menu_item( $menu_id, 0, $args );
 	}
 }
+
+/**
+ * Delete auto-draft posts associated with the supplied changeset.
+ *
+ * @since 4.8.0
+ * @access private
+ *
+ * @param int $post_id Post ID for the customize_changeset.
+ */
+function _wp_delete_customize_changeset_dependent_auto_drafts( $post_id ) {
+	$post = get_post( $post_id );
+
+	if ( ! $post || 'customize_changeset' !== $post->post_type ) {
+		return;
+	}
+
+	$data = json_decode( $post->post_content, true );
+	if ( empty( $data['nav_menus_created_posts']['value'] ) ) {
+		return;
+	}
+	remove_action( 'delete_post', '_wp_delete_customize_changeset_dependent_auto_drafts' );
+	foreach ( $data['nav_menus_created_posts']['value'] as $post_id ) {
+		if ( ! empty( $post_id ) && 'auto-draft' === get_post_status( $post_id ) ) {
+			wp_delete_post( $post_id, true );
+		}
+	}
+	add_action( 'delete_post', '_wp_delete_customize_changeset_dependent_auto_drafts' );
+}

wp-includes/theme.php

@@ -3059,3 +3059,65 @@ function is_customize_preview() {
 
 	return ( $wp_customize instanceof WP_Customize_Manager ) && $wp_customize->is_preview();
 }
+
+/**
+ * Make sure that auto-draft posts get their post_date bumped to prevent premature garbage-collection.
+ *
+ * When a changeset is updated but remains an auto-draft, ensure the post_date
+ * for the auto-draft posts remains the same so that it will be
+ * garbage-collected at the same time by `wp_delete_auto_drafts()`. Otherwise,
+ * if the changeset is updated to be a draft then update the posts
+ * to have a far-future post_date so that they will never be garbage collected
+ * unless the changeset post itself is deleted.
+ *
+ * @since 4.8.0
+ * @access private
+ * @see wp_delete_auto_drafts()
+ *
+ * @param string   $new_status Transition to this post status.
+ * @param string   $old_status Previous post status.
+ * @param \WP_Post $post       Post data.
+ * @global wpdb $wpdb
+ */
+function _wp_keep_alive_customize_changeset_dependent_auto_drafts( $new_status, $old_status, $post ) {
+	global $wpdb;
+	unset( $old_status );
+
+	// Short-circuit if not a changeset or if the changeset was published.
+	if ( 'customize_changeset' !== $post->post_type || 'publish' === $new_status ) {
+		return;
+	}
+
+	if ( 'auto-draft' === $new_status ) {
+		/*
+		 * Keep the post date for the post matching the changeset
+		 * so that it will not be garbage-collected before the changeset.
+		 */
+		$new_post_date = $post->post_date;
+	} else {
+		/*
+		 * Since the changeset no longer has an auto-draft (and it is not published)
+		 * it is now a persistent changeset, a long-lived draft, and so any
+		 * associated auto-draft posts should have their dates
+		 * pushed out very far into the future to prevent them from ever
+		 * being garbage-collected.
+		 */
+		$new_post_date = gmdate( 'Y-m-d H:i:d', strtotime( '+100 years' ) );
+	}
+
+	$data = json_decode( $post->post_content, true );
+	if ( empty( $data['nav_menus_created_posts']['value'] ) ) {
+		return;
+	}
+	foreach ( $data['nav_menus_created_posts']['value'] as $post_id ) {
+		if ( empty( $post_id ) || 'auto-draft' !== get_post_status( $post_id ) ) {
+			continue;
+		}
+		$wpdb->update(
+			$wpdb->posts,
+			array( 'post_date' => $new_post_date ), // Note wp_delete_auto_drafts() only looks at this this date.
+			array( 'ID' => $post_id )
+		);
+		clean_post_cache( $post_id );
+	}
+}

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.8-beta1-40675';
+$wp_version = '4.8-beta1-40676';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.