Windows Terminal breaks when the script hits the end of visible terminal window

[farag2]

Windows Terminal version

1.16.10262.0

Windows build number

10.0.22621

Other Software

function ShowMenu
{
	[CmdletBinding()]
	param
	(
		[Parameter(Mandatory = $true)]
		[array]
		$Menu
	)

	$minY = [Console]::CursorTop
	$y = [Math]::Max([Math]::Min(1, $Menu.Count), 0)

	do
	{
		[Console]::CursorTop = $minY
		[Console]::CursorLeft = 0
		$i = 0
		foreach ($item in $Menu)
		{
			if ($i -ne $y)
			{
				Write-Information -MessageData ('  {1}  ' -f ($i+1), $item) -InformationAction Continue
			}
			else
			{
				Write-Information -MessageData ('[ {1} ]' -f ($i+1), $item) -InformationAction Continue
			}
			$i++
		}

		$k = [Console]::ReadKey()
		switch ($k.Key)
		{
			"UpArrow"
			{
				if ($y -gt 0)
				{
					$y--
				}
			}
			"DownArrow"
			{
				if ($y -lt ($Menu.Count - 1))
				{
					$y++
				}
			}
			"Enter"
			{
				return $Menu[$y]
			}
		}
	}
	while ($k.Key -notin ([ConsoleKey]::Escape, [ConsoleKey]::Enter))

}

# Get disks letters
ShowMenu -Menu @((Get-CimInstance -ClassName CIM_LogicalDisk | Where-Object -FilterScript {$_.DriveType -eq 3}).DeviceID | Sort-Object)

Steps to reproduce

If we run this snippet that just shows disks letters, after we hit the end of visible windows area we cannot use brackets to choose: disks letters overlap each other when I use arrow down/up.

The bug is not reproducable neither in bare powershell.exe (5.1), nor in pwsh.exe (7.3)

Recorded video with the bug

bug.mp4

Bare powershell.exe (5.1)

notbugged.mp4

Expected Behavior

Regardless we hit the visible console window, we disks letters shoudn't overlap each other.

Actual Behavior

Disks letters overlap each other in the console

[zadjii-msft]

Can you test something for me? In bare powershell, can you fill up the entire buffer, then try to repro the bug? Something like a gci -Recurse should fill it up pretty quickly. Just make sure that there's enough output so that the scrollbar is all the way at the bottom of the console window.

Once the buffer's full, try reproing this again/?

My hunch is that this never worked at the bottom of the buffer, and as far as the Terminal is concerned, the bottom of the viewport is the bottom of the buffer.

[farag2]

@zadjii-msft, did what you asked. It works in bare powershell.exe (5.1).

2023-03-14.223640.mp4

[lhecker]

@farag2 No, try filling your entire scrollback buffer. Your scrollbar shows that there's still some space left. Here's a faster way than gci -Recurse to do so:

[Console]::CursorTop = [Console]::BufferHeight - 1

I agree with @zadjii-msft here: This has never worked reliably, and if you try the above it should show that. The problem is that once the buffer is full, writing more text will scroll the text upwards, but cursor positions will remain relative to the scrollback buffer! They don't get scrolled up with the content.

[farag2]

Yeah, I got it. It really occurs in powershell.exe too. I just wanted to know whether this is a Terminal bug only. You're right.

This code fixes the bug. Thank you guys! 🐱

[System.Console]::BufferHeight += $Menu.Count
$minY = [Console]::CursorTop
$y = [Math]::Max([Math]::Min($Default, $Menu.Count), 0)