vterm gets locked up when pasting password into a prompt

[doctordesh]

Hello!

When using a password manager it's practice to copy the password from the manager and then paste into the place where it's needed, like a prompt in a terminal program of some sort. For a long time this has not worked for me in vterm and I have boiled it down to it's components.

How to reproduce:

emacs -q

Paste this code into *scratch* and use eval-region

(package-initialize)
(require 'use-package)
(use-package vterm)
(setq vterm-timer-delay nil) ;; <-- the problematic line

Now, open up a vterm terminal with M-x vterm RET

Use this bash line to create a prompt

bash -c 'read -s -p "Password: " pwd; echo $pwd;'

If you want to double-check, try to type something and then hitting RET to make sure it works.

Next, try to paste something, and paste is correctly bound to vterm-yank. Then (before I hit RET, just the yank), my emacs locks up completely, reacting to nothing except C-g. When C-g is hit, I can hit RET and get my password through.

This only happens when vterm-timer-delay is set to nil.

Emacs version: GNU Emacs 29.3 (build 2, aarch64-apple-darwin23.2.0, NS appkit-2487.30 Version 14.2.1 (Build 23C71)) of 2024-04-03 (if I remember correctly, I've had this issue since at least 28).

Vterm version: 20240325.1551

All the best!