Followup r82727, improve comments, cast return value to bool

includes/Article.php

@@ -2431,6 +2431,9 @@ class Article {
 
 	/**
 	 * Add this page to $wgUser's watchlist
+	 *
+	 * This is safe to be called multiple times
+	 *
 	 * @return bool true on successful watch operation
 	 */
 	public function doWatch() {

includes/api/ApiBase.php

@@ -602,8 +602,8 @@ abstract class ApiBase {
 					$userOption = $titleObj->exists()
 						? 'watchdefault' : 'watchcreations';
 				}
-				# If the corresponding user option is true, watch, don't
-				return $wgUser->getOption( $userOption ) ? true : false;
+				# Watch the article based on the user preference
+				return (bool)$wgUser->getOption( $userOption );
 
 			case 'nochange':
 				return $userWatching;