Merge 66b6bb0 into 7910d6b

js/customize-snapshots.js

@@ -1083,7 +1083,7 @@
 		},
 
 		/**
-		 * Remove 'customize_changeset_status' if its already set.
+		 * Remove 'customize_changeset_status' if its already set; replace with customize_snapshots_create_revision param.
 		 *
 		 * @return {void}
 		 */
@@ -1113,6 +1113,7 @@
 				isSameStatus = api.state( 'changesetStatus' ).get() === originalOptions.data.customize_changeset_status;
 				if ( 'customize_save' === originalOptions.data.action && isSameStatus && options.data ) {
 					options.data = removeParam( options.data, 'customize_changeset_status' );
+					options.data += '&customize_snapshots_create_revision=1';
 				}
 			} );
 		}

php/class-customize-snapshot-manager.php

@@ -104,6 +104,8 @@ function hooks() {
 		add_action( 'admin_bar_menu', array( $this, 'remove_all_non_snapshot_admin_bar_links' ), 100000 );
 		add_action( 'wp_before_admin_bar_render', array( $this, 'print_admin_bar_styles' ) );
 		add_filter( 'removable_query_args', array( $this, 'filter_removable_query_args' ) );
+		add_filter( 'wp_save_post_revision_post_has_changed', array( $this, '_filter_revision_post_has_changed' ), 20, 3 );
+		add_action( 'save_post_customize_changeset', array( $this, 'create_initial_changeset_revision' ) );
 		add_filter( 'wp_insert_post_data', array( $this, 'prepare_snapshot_post_content_for_publish' ) );
 	}
 
@@ -342,6 +344,37 @@ public function snapshot() {
 		return $this->snapshot;
 	}
 
+	/**
+	 * Create initial changeset revision.
+	 *
+	 * This should be removed once #30854 is resolved.
+	 *
+	 * @link https://core.trac.wordpress.org/ticket/30854
+	 */
+	public function create_initial_changeset_revision( $post_id ) {
+		if ( 0 === count( wp_get_post_revisions( $post_id ) ) ) {
+			wp_save_post_revision( $post_id );
+		}
+	}
+
+	/**
+	 * When a customize_save Ajax action is being made, ensure a revision is allowed if customize_snapshots_create_revision query param is present.
+	 *
+	 * @see \WP_Customize_Manager::_filter_revision_post_has_changed()
+	 *
+	 * @param bool     $post_has_changed Whether the post has changed.
+	 * @param \WP_Post $last_revision    The last revision post object.
+	 * @param \WP_Post $post             The post object.
+	 * @return bool Whether a revision should be made.
+	 */
+	public function _filter_revision_post_has_changed( $post_has_changed, $last_revision, $post ) {
+		unset( $last_revision );
+		if ( 'customize_changeset' === $post->post_type && ! empty( $_POST['customize_snapshots_create_revision'] ) ) {
+			$post_has_changed = true;
+		}
+		return $post_has_changed;
+	}
+
 	/**
 	 * Prepare snapshot post content for publishing.
 	 *