Conemu: Git for Windows 2.28.0-rc2 going up in pager glitches

[cmcqueen]

See git-for-windows/git#2767 for details.

• Git for Windows 2.28.0-rc2
• ConEmu 200713

I do git log, go down a page in the log — it's fine. Then go up a page — it glitches the text sluggishly on the top line, and doesn't show it properly.

However:

• This doesn't happen with Git for Windows 2.26.2.
• This doesn't happen with Git for Windows 2.28.0-rc2 in a plain cmd window.

So I can't tell if it should be considered a Git bug or a ConEmu bug.

[Maximus5]

How do you run your shell and git?

[Maximus5]

This doesn't happen with Git for Windows 2.28.0-rc2 in a plain cmd window.

With same code page, buffer and console size?

[cmcqueen]

How do you run your shell and git?

I run ConEmu and use its default shell (cmd).

With same code page, buffer and console size?

According to chcp, it's code page 850 in both.

According to powershell -command "&{$H=get-host;$H.ui.rawui;}", for plain cmd:

BufferSize            : 120,9001
WindowSize            : 120,30
MaxWindowSize         : 120,63
MaxPhysicalWindowSize : 240,63

For ConEmu:

BufferSize            : 155,32766
WindowSize            : 155,52
MaxWindowSize         : 155,203
MaxPhysicalWindowSize : 155,52

[Maximus5]

So the buffer differs. You should compare git behavior in similar conditions

[WildOrangutan]

I've tried running ConEmu with smaller, similar and bigger buffer sizes, and didn't notice any improvements. I also did similar with cmd and couldn't reproduce this problem.

[cmcqueen]

So the buffer differs. You should compare git behavior in similar conditions

Even though the buffer differs, and they're not similar conditions, the bug does not manifest with Git for Windows 2.26.2. So I don't think buffer differences is the root cause.

Have you (@Maximus5) tried this yourself? I assume it's not too difficult for you to try out Git for Windows 2.28.0-rc2 and see if you can reproduce the issue.

[kceiw]

This happens to me too when I try to scroll up the log from 'git log'. Not just 'git log', it also happens in 'git diff'. It seems it has to do with the pager or something.

I'm using
git: git version 2.28.0.windows.1
ConEmu: 200713 [64] {Preview}

This only happens in ConEmu. It doesn't happens in standard alone CMD.exe or PowerShell.exe.

[kceiw]

I found a "workaround" after updating to latest ConEmu: 202011 Preview.

I use VIM 8.2 and use command ":sh" to go to the shell. "git log" and "git diff" work correctly when I scroll up and down. But other than that, running directly on ConEmu still has this issue.

[jruffin]

I can confirm the same issue with the following versions:

git: 2.28 and 2.29
ConEmu: 202011, 200928, 190108 (all Preview), 161206 (Stable)

Window size: 145 x 72. Code page 850.

Results of calling the powershell command above in cmd.exe and ConEmu 202011, respectively:

```BufferSize : 145,9001
WindowSize : 145,72
MaxWindowSize : 145,86
MaxPhysicalWindowSize : 320,86

```BufferSize            : 145,32766
WindowSize            : 145,72
MaxWindowSize         : 145,275
MaxPhysicalWindowSize : 145,72

The error happens in ConEmu, but not in cmd with the exact same window size and code page. Detaching the ConEmu console on which it happens into its own separate CMD window makes the issue disappear.

Downgrading to git 2.27 also solves it.

[wesleywerner]

For what it is worth, I found a temporary work-around: Toggle bufferHeight mode OFF. Then pager scrolling works as expected. This is a button on the toolbar, or assign your own hotkey to the bufferHeight entry.

[Maximus5]

Yes, backscroll buffer height is the reason of the issue.
I'll try to fix it.

[Maximus5]

https://conemu.github.io/blog/2020/11/22/Build-201122.html

[jruffin]

Many thanks!

[dodmi]

Thank you for working on this issue.
It looks much better here, too.
But it seems, it's still not perfect, as another user reports glitches with the new version: https://github.com/Maximus5/ConEmu/issues/2206#issue-748742306

[Maximus5]

Should be fixed in https://conemu.github.io/blog/2020/11/23/Build-201123.html