Escape sequences are not stripped from the tab title

[j4james]

Windows Terminal version

1.12.3472.0

Windows build number

10.0.19041.1415

Other Software

No response

Steps to reproduce

1. Edit the settings.json file.
2. Set the default tab title with an escape sequence like this: "tabTitle": "\u001b[41m"
3. Start a cmd shell

Expected Behavior

The escape character should be stripped from the title.

Actual Behavior

The escape character is left in the title when propagated over conpty, so it ends up being interpreted as a background color change in the terminal.

We do already sanitize the title in DoSrvSetConsoleTitleW, which covers title changes via the console API, but in this case the CONSOLE_INFORMATION::SetTitle method is being called directly from the AllocateConsole method on startup:

terminal/src/host/consoleInformation.cpp

Line 130 in 7061c54

gci.SetTitle(title);

My suggestion is we move the sanitization from DoSrvSetConsoleTitleW into the CONSOLE_INFORMATION::SetTitle method, so we can be sure it's applied in all cases.

[zadjii-msft]

That's a great catch, and the suggestion sounds fine to me!

> inb4 some enterprise has been intentionally putting an escape char in their titles for god knows what reason
🤣

[j4james]

inb4 some enterprise has been intentionally putting an escape char in their titles for god knows what reason

I did actually wonder about that, but the current sanitization code only runs when we're in pty mode, and I was planning to retain that condition, so crazy enterprise code should still work as usual on conhost if it comes to that.