From d0a3484b048b8c177e62d66aecb03f5928f7a857 Mon Sep 17 00:00:00 2001
From: Cyril Walle <cyril.walle@protonmail.com>
Date: Fri, 12 Feb 2021 18:54:55 +0100
Subject: [PATCH] fix: handle invalid filenames when keepExtensions is true

---
 src/Formidable.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/Formidable.js b/src/Formidable.js
index 0d4e2c6e..0fb0951c 100644
--- a/src/Formidable.js
+++ b/src/Formidable.js
@@ -480,6 +480,10 @@ class IncomingForm extends EventEmitter {
   }
 
   _getExtension(str) {
+    if (!str) {
+      return '';
+    }
+
     const basename = path.basename(str);
     const firstDot = basename.indexOf('.');
     const lastDot = basename.lastIndexOf('.');