From 4f1e4ffa4eefcbfc4af310738ce0f59279f9cc94 Mon Sep 17 00:00:00 2001
From: Alex Rickabaugh <alx+alxhub@alxandria.net>
Date: Thu, 13 Jul 2017 12:28:20 -0700
Subject: [PATCH] fix(common): don't guess Content-Type for FormData bodies
 (#18104)

Fixes #18096
---
 packages/common/http/src/request.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/common/http/src/request.ts b/packages/common/http/src/request.ts
index 2e55613ff6..7673e71f0e 100644
--- a/packages/common/http/src/request.ts
+++ b/packages/common/http/src/request.ts
@@ -266,9 +266,9 @@ export class HttpRequest<T> {
     if (this.body === null) {
       return null;
     }
-    // FormData instances are URL encoded on the wire.
+    // FormData bodies rely on the browser's content type assignment.
     if (isFormData(this.body)) {
-      return 'multipart/form-data';
+      return null;
     }
     // Blobs usually have their own content type. If it doesn't, then
     // no type can be inferred.