From b4e3693226cd0efa18fc23fcbacc64ee90ba4020 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Niklas=20Hamb=C3=BCchen?= <mail@nh2.me>
Date: Fri, 14 Apr 2023 10:58:52 +0200
Subject: [PATCH] Fix HEAD not being retried for HTTP 500 category responses.
 See #579

---
 lib/upload.js | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/upload.js b/lib/upload.js
index 83dfa35b..82a16fdf 100644
--- a/lib/upload.js
+++ b/lib/upload.js
@@ -616,6 +616,14 @@ class BaseUpload {
           this._emitHttpError(req, res, 'tus: upload is currently locked; retry later')
           return
         }
+        if (inStatusCategory(status, 500)) {
+          // Run retry logic if the server has an error, e.g. 502 Bad Gateway when
+          // proxied server is temporarily down. See issue #579.
+          // Since we want to retry, do not clear `this.url` and do not
+          // create a new upload.
+          this._emitHttpError(req, res, 'tus: resuming upload resulted in HTTP 500 category error')
+          return
+        }
 
         if (inStatusCategory(status, 400)) {
           // Remove stored fingerprint and corresponding endpoint,