Delete errorneous empty content length header (#53843)

fixes #53822 PR #53368 introduced a regression causing fetch with custom headers to fail in safari. There are known issues with uncidi when a content-length: 0 header exists. When performing a custom fetch in safari, this header is present. When performing a custom fetch in chrome, this header is not present. Co-authored-by: Zack Tanner <[email protected]>
vercel · Aug 10, 2023 · 9bb10b1 · 9bb10b1
1 parent 6f7ffad
commit 9bb10b1
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/packages/next/src/server/lib/server-ipc/utils.ts b/packages/next/src/server/lib/server-ipc/utils.ts
@@ -17,6 +17,12 @@ export const filterReqHeaders = (
   headers: Record<string, undefined | string | number | string[]>,
   forbiddenHeaders: string[]
 ) => {
+  // Some browsers are not matching spec and sending Content-Length: 0. This causes issues in undici
+  // https://github.com/nodejs/undici/issues/2046
+  if (headers['content-length'] && headers['content-length'] === '0') {
+    delete headers['content-length']
+  }
+
   for (const [key, value] of Object.entries(headers)) {
     if (
       forbiddenHeaders.includes(key) ||