ENABLE_VIRTUAL_TERMINAL_PROCESSING skips null characters

[alabuzhev]

Environment

Windows build number: 10.0.19041.746
Windows Terminal version (if applicable): No

Any other software? No

Steps to reproduce

Historically null characters in console output have been replaced with spaces by the host.
Now, when ENABLE_VIRTUAL_TERMINAL_PROCESSING is set, these characters are completely removed from the output instead.
It breaks screen output logic if the application relies on the previous behavior.

Compile and run the following code:

#include <windows.h>

int main()
{
	const wchar_t Str[] = L"ABC\0XYZ\n";

	const auto Out = GetStdHandle(STD_OUTPUT_HANDLE);

	const auto print = [&]
	{
		DWORD n;
		WriteConsole(Out, Str, ARRAYSIZE(Str) - 1, &n, {});
	};

	print();

	DWORD Mode;
	GetConsoleMode(Out, &Mode);
	SetConsoleMode(Out, Mode | ENABLE_VIRTUAL_TERMINAL_PROCESSING);

	print();
}

Expected behavior

ABC XYZ
ABC XYZ

Actual behavior

ABC XYZ
ABCXYZ

[skyline75489]

Related: #6265 , #8680

[zadjii-msft]

Yea this is totally by design. ENABLE_VIRTUAL_TERMINAL_PROCESSING changes a whole bunch of other things about the way the console behaves too, this is just one part of it. If you want the console to act like a terminal, then you'll need to output text like you're connected to a terminal 😉

There's also #1825, #3015, #4171 all relevant in this space.