PWA reserved-device-name POC

This page is an installable PWA whose manifest name is COM1. On Windows, click the omnibox Install button (or use the menu → "Install COM1...") and accept the dialog.

Chrome's browser process will then attempt to create %USERPROFILE%\Desktop\COM1.lnk and <profile>\Web Applications\_crx_<id>\COM1.ico. Because GetSanitizedFileName() does not call net::IsReservedNameOnWindows(), on Windows 10 (and Win11 pre-22H2) those paths resolve to \\.\COM1 and the .lnk byte stream — including the manifest description field above — is written to whatever serial hardware is attached to COM1, bypassing the WebSerial permission surface.

Edit manifest.json and change "name" to "PRN" / "LPT1" / "AUX" / "NUL" to target other DOS devices.