From 9bf94ad50ff9a408adf23357f51dcf403d4580b2 Mon Sep 17 00:00:00 2001
From: Julian Lam <julian@nodebb.org>
Date: Fri, 26 Feb 2021 09:58:48 -0500
Subject: [PATCH] fix: allow interstitial callbacks to be functional (no cb
 required)

---
 src/controllers/authentication.js | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/controllers/authentication.js b/src/controllers/authentication.js
index dece1978e9..a96af6d45f 100644
--- a/src/controllers/authentication.js
+++ b/src/controllers/authentication.js
@@ -150,7 +150,14 @@ authenticationController.registerComplete = function (req, res, next) {
 		const callbacks = data.interstitials.reduce((memo, cur) => {
 			if (cur.hasOwnProperty('callback') && typeof cur.callback === 'function') {
 				req.body.files = req.files;
-				memo.push(cur.callback && cur.callback.constructor && cur.callback.constructor.name === 'AsyncFunction' ? cur.callback : util.promisify(cur.callback));
+				if (
+					(cur.callback.constructor && cur.callback.constructor.name === 'AsyncFunction') ||
+					cur.callback.length === 2	// non-async function w/o callback
+				) {
+					memo.push(cur.callback);
+				} else {
+					memo.push(util.promisify(cur.callback));
+				}
 			}
 
 			return memo;