From 9e87596bd6e7a472eea1979e14219ec4bf9267a6 Mon Sep 17 00:00:00 2001
From: Darsh Patel <darshkpatel@gmail.com>
Date: Mon, 10 May 2021 14:09:18 +0530
Subject: [PATCH] Fix: Non-writable pages/_app breaks build (#24849)

Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>
---
 .../webpack/loaders/next-serverless-loader/page-handler.ts  | 2 +-
 packages/next/next-server/server/next-server.ts             | 2 +-
 packages/next/server/lib/find-page-file.ts                  | 6 +++---
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/next/build/webpack/loaders/next-serverless-loader/page-handler.ts b/packages/next/build/webpack/loaders/next-serverless-loader/page-handler.ts
index ccbfe30d15050..35682cfc37225 100644
--- a/packages/next/build/webpack/loaders/next-serverless-loader/page-handler.ts
+++ b/packages/next/build/webpack/loaders/next-serverless-loader/page-handler.ts
@@ -412,7 +412,7 @@ export function getPageHandler(ctx: ServerlessHandlerCtx) {
 
       if (err.code === 'ENOENT') {
         res.statusCode = 404
-      } else if (err.code === 'DECODE_FAILED') {
+      } else if (err.code === 'DECODE_FAILED' || err.code === 'ENAMETOOLONG') {
         // TODO: better error?
         res.statusCode = 400
       } else {
diff --git a/packages/next/next-server/server/next-server.ts b/packages/next/next-server/server/next-server.ts
index abad677883798..0b367f43a1a4e 100644
--- a/packages/next/next-server/server/next-server.ts
+++ b/packages/next/next-server/server/next-server.ts
@@ -1255,7 +1255,7 @@ export default class Server {
         return
       }
     } catch (err) {
-      if (err.code === 'DECODE_FAILED') {
+      if (err.code === 'DECODE_FAILED' || err.code === 'ENAMETOOLONG') {
         res.statusCode = 400
         return this.renderError(null, req, res, '/_error', {})
       }
diff --git a/packages/next/server/lib/find-page-file.ts b/packages/next/server/lib/find-page-file.ts
index 149a93f8893cb..08da65906416e 100644
--- a/packages/next/server/lib/find-page-file.ts
+++ b/packages/next/server/lib/find-page-file.ts
@@ -1,9 +1,9 @@
 import { join, sep as pathSeparator, normalize } from 'path'
 import chalk from 'chalk'
-import { isWriteable } from '../../build/is-writeable'
 import { warn } from '../../build/output/log'
 import { promises } from 'fs'
 import { denormalizePagePath } from '../../next-server/server/normalize-page-path'
+import { fileExists } from '../../lib/file-exists'
 
 async function isTrueCasePagePath(pagePath: string, pagesDir: string) {
   const pageSegments = normalize(pagePath).split(pathSeparator).filter(Boolean)
@@ -31,14 +31,14 @@ export async function findPageFile(
       const relativePagePath = `${page}.${extension}`
       const pagePath = join(rootDir, relativePagePath)
 
-      if (await isWriteable(pagePath)) {
+      if (await fileExists(pagePath)) {
         foundPagePaths.push(relativePagePath)
       }
     }
 
     const relativePagePathWithIndex = join(page, `index.${extension}`)
     const pagePathWithIndex = join(rootDir, relativePagePathWithIndex)
-    if (await isWriteable(pagePathWithIndex)) {
+    if (await fileExists(pagePathWithIndex)) {
       foundPagePaths.push(relativePagePathWithIndex)
     }
   }