Undeterministic glitches of text with colored background

[mcpiroman]

Environment

bd5cae1

Steps to reproduce

Run program of this kind:

int main()
{
	cout << "\x1B[41m";
	cout << "X Red ";
	cout << "\x1B[42m";
	cout << "Green\n";
	cout << "\x1B[43m";
	cout << "Yellow ";
	cout << "\x1B[44m";
	cout << "Blue";
	cout << "\x1B[0m";
	return 0;
}

Expected behavior

Actual behavior

[j4james]

Unless you have set the VirtualTerminalLevel registry setting, those escape sequences shouldn't be interpreted at all, so your program really shouldn't be displaying any colors. Try running it from a conhost shell to see what I mean.

However, because the Windows Terminal is passing your output through at conpty pipe, I suspect it's accidentally interpreting those escape sequences on the other side of the pipe, and that's when things start to go wrong.

I believe this is a know bug - issue #1965 describes a similar situation.

[DHowett-MSFT]

Correct, this just looks like the same issue. If you use SetConsoleMode to turn on ENABLE_VIRTUAL_TERMINAL_PROCESSING explicitly, does it work fine?

[mcpiroman]

@DHowett-MSFT it does