From f2f9090a50f42bb894fc7ea3db48e1b125ea85fa Mon Sep 17 00:00:00 2001
From: Luke Fender <lfender@rentpath.com>
Date: Tue, 29 Dec 2020 11:12:36 -0500
Subject: [PATCH] Ignore emacs lockfiles (#20497)

Fixes: https://github.com/vercel/next.js/issues/15278

> Bug report

> When using next dev with emacs, as you develop, emacs creates symbolic link files starting with .# as lock files. Next.js seems to attempt to load these but fails, spewing out errors constantly.

Prevents dev server from crashing when emacs creates lockfiles

tested with:

- GNU Emacs 27.1
- OSX 11.1
- Node v15.4.0
---
 .gitignore                            |  1 +
 packages/next/build/webpack-config.ts | 10 +++++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/.gitignore b/.gitignore
index bc9176f4c40b..f043ec68d93f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,6 +25,7 @@ test/**/next-env.d.ts
 
 # Editors
 **/.idea
+**/.#*
 
 # examples
 examples/**/out
diff --git a/packages/next/build/webpack-config.ts b/packages/next/build/webpack-config.ts
index 462d51590348..4b732e9681e7 100644
--- a/packages/next/build/webpack-config.ts
+++ b/packages/next/build/webpack-config.ts
@@ -712,6 +712,8 @@ export default async function getBaseWebpackConfig(
     callback()
   }
 
+  const emacsLockfilePattern = '**/.#*'
+
   let webpackConfig: webpack.Configuration = {
     externals: !isServer
       ? // make sure importing "next" is handled gracefully for client
@@ -788,7 +790,13 @@ export default async function getBaseWebpackConfig(
       }
     },
     watchOptions: {
-      ignored: ['**/.git/**', '**/node_modules/**', '**/.next/**'],
+      ignored: [
+        '**/.git/**',
+        '**/node_modules/**',
+        '**/.next/**',
+        // can be removed after https://github.com/paulmillr/chokidar/issues/955 is released
+        emacsLockfilePattern,
+      ],
     },
     output: {
       ...(isWebpack5