Ordinary browser launches skip a help probe
pull request 15037, merged into quattro, runs the browser's private-window probe only for a private launch. Ordinary launches had been starting Firefox, Zen, or LibreWolf to read the help text. The merge is not in version 4.0.4.
The launcher had been running the browser's help command on every launch, including every link, to learn the private-window flag. David Heinemeier Hansson said Chromium answers in about 3ms, while Firefox, Zen, or LibreWolf starts the whole browser to print that help. The merged script runs the probe only when the launch passes a private flag.
Other launches leave their arguments unchanged. The flag defaults to the ordinary private switch, so a normal launch does not need the probe. David Heinemeier Hansson opened and merged the change.