Scrolling doesn't work properly in latest insider beta

[bitcrazed]

From @warpdesign on April 22, 2017 10:22

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• Your Windows build number: (Type ver at a Windows Command Prompt)
  10.0.16179

• What you're doing and what's happening: (Copy&paste specific commands and their output, or include screen shots)
  I ran npm installed which produced lots of output text and wanted to scroll up to read the text I missed.

• What's wrong / what should be happening instead:
  Instead of seeing the output from the command I just typed, I saw output from a command I ran hours ago.

• Strace of the failing command, if applicable: (If <cmd> is failing, then run strace -o strace.txt -ff <cmd>, and post the strace.txt output here)

Copied from original issue: microsoft/WSL#1984

[bitcrazed]

From @zadjii-msft on April 24, 2017 15:39

Gonna go out on a limb and say this has to do with the scroll margins, again.

MSFT:11647773 currently tracks what I think is this issue, though I'll add this to that bug to make sure they're the same.

@warpdesign any chance that before you ran npm install ..., you had run apt install ...? I'm pretty sure that apt is a reliable repro for this behavior, but I don't know if npm is yet.

[bitcrazed]

From @Po-wei on May 12, 2017 5:52

I have the same scrolling problem, too. What's more, when I encounter this issue, typing "clear" would let me cannot scroll up(The scrolling bar was fixed on the top, and the previous information was gone.)

[bitcrazed]

From @zadjii-msft on May 30, 2017 22:31

Wadda ya know, I fixed this issue this morning. On it's way out to Insider's now :)

[bitcrazed]

From @Po-wei on June 3, 2017 8:11

@zadjii-msft When can i get this update from regular Windows Update?

[bitcrazed]

From @zadjii-msft on June 5, 2017 16:16

If you're not on Insiders, then I think the best I can tell you is Soon^TM. It'll come out with the Fall Creator's Update, but I don't know when that will officially be released.

[bitcrazed]

From @MerkaST on December 6, 2017 23:17

This appears to still happen with the Fall Creator's Update. I'm on build 16299.64 and running an apt install (or remove or autoremove, I'd assume all commands that use the progress bar) command that produces output longer than one window right after opening WSL will exhibit this behaviour, ie. have missing scrollback content.

[bitcrazed]

From @zadjii-msft on December 8, 2017 17:32

Hmmm. Okay so i think I get what's happening. Basically, the "scroll margins" that apt sets are at a fixed point in the buffer. So anything that would scrollback off of it, is just lost instead.

The right way to do this is to probably instead shift the whole viewport down a line (including the buffer-relative margin settings), then scroll the contents of the margins up a line, so that the top line is off of the viewport, in the "scrollback".

Filing a new bug to take a look at this later this release cycle.

[zadjii-msft]

I just submitted a bug fix that should fix the issue of apt install output not getting moved into scrollback when it scrolls off the top of the viewport.

Should be in whatever the next official Windows release is called (2Fall2CreatorsUpdate)