patch 8.2.2880: unified diff fails if actually used Commit: https://github.com/vim/vim/commit/ad5c178a191cf2cf37a27c2a789d7afda3879831 Author: glacambre <code@lacamb.re> Date: Mon May 24 14:20:53 2021 +0200 patch 8.2.2880: unified diff fails if actually used Problem: Unified diff fails if actually used. Solution: Invoke :diffupdate in the test. Fix the check for working external diff. (Ghjuvan Lacambre, Christian Brabandt, closes #8197)

#!/bin/bash
set -e

apt-get install -y xvfb

cat <<EOT >/etc/systemd/system/xvfb.service
[Unit]
Description=X Virtual Frame Buffer Service
After=network.target
[Service]
ExecStart=/usr/bin/Xvfb :99 -screen 0 1024x768x24
[Install]
WantedBy=multi-user.target
EOT

systemctl enable xvfb.service
systemctl start xvfb.service