Confusing error when listening with domain socket on already-existing path

[XMB5]

• Version: v11.0.0
• Platform: Linux computer_name 4.15.0-38-generic Add a Gitter chat badge to README.md #41-Ubuntu SMP Wed Oct 10 10:59:38 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
• Subsystem: net

When listening with a domain socket on a path that already exists, node should throw the error listen EADDRINUSE: address already in use. However, when writableAll or readableAll is set to true, the error message is confusing and misleading: TypeError: Cannot read property 'fchmod' of null.

Recreate the desired effect by running node -e "require('net').createServer().listen({path:'/'})", and recreate the confusing error message with node -e "require('net').createServer().listen({path:'/',writableAll:true})".

[oyyd]

Because it failed to create Pipe on / and the "error" event would have been emitted in the next tick. I would like to submit a PR to fix this.