Make sure conpty is flushed before clearing scrollback #13324
Conversation
ghost
added
Area-Server
DHowett
added
the
AutoMerge
|
Hello @DHowett! Because this pull request has the p.s. you can customize the way I help with merging this pull request, such as holding this pull request until a specific person approves. Simply @mention me (
|
## Summary of the Pull Request When you execute a `cls` in the cmd shell, or `Clear-Host` in PowerShell, we have a pair of shims that attempt to detect those operations and forward an `ED3` sequence to conpty to clear the scrollback. If there was a linefeed at the bottom of the viewport immediately prior to those functions being called, that event might still be pending, and only forwarded to conpty after the `ED3`. The result then is a line pushed into the scrollback that shouldn't be there. This PR tries to avoid that situation by forcing the renderer to flush before the `ED3` sequence is sent. ## References The `cls` and `Clear-Host` shims were originally added in PR #5627. ## PR Checklist * [x] Closes #5770 * [x] Closes #13320 * [x] CLA signed. * [ ] Tests added/passed * [ ] Documentation updated. * [ ] Schema updated. * [ ] I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx ## Validation Steps Performed I've manually tested in PowerShell with `echo Hello; Clear-Host` (this is the only way I could reliably reproduce the original problem), and in the cmd shell with `cls`. Both cases are now working as expected. (cherry picked from commit 08c2f35) Service-Card-Id: 83388911 Service-Version: 1.14
|
🎉 Handy links: |
|
🎉 Handy links: |
I just installed the latest stable Windows Terminal Version: 1.14.1862.0 directly from the releases page; and it looks that despite being emailed this morning that this PR that was implemented in today's releases addressed my issue from 2020, it did not. I'm still experiencing the same thing I did back then: #4461 |
|
@jrd-lewis I think closing #4461 as a duplicate of #3126 was probably a mistake. Your problem was regarding the command history not being cleared, while #3126 (and this PR) has to do with clearing the scroll-back buffer. That said, the PowerShell history isn't actually something that is controlled by the terminal, so there's nothing we could do about that anyway. And I suspect it may be working as intended, since you're clearing the PSConsoleReadLine history which I believe is separate from the actual PowerShell history. But I think the best place to get further info would be in the PowerShell/PSReadLine repository. Just doing a quick scan, I found PowerShell/PSReadLine/issues/1247, which may be relevant. I'm sorry you weren't directed there earlier. |
|
Thanks for this, @j4james. You're right -- I shouldn't have closed that as a duplicate. I completely overlooked the fact that @jrd-lewis was talking about command history. Even though he had said, "press the up arrow." 🤦🏻 |
Summary of the Pull Request
When you execute a
clsin the cmd shell, orClear-HostinPowerShell, we have a pair of shims that attempt to detect those
operations and forward an
ED3sequence to conpty to clear thescrollback.
If there was a linefeed at the bottom of the viewport immediately
prior to those functions being called, that event might still be
pending, and only forwarded to conpty after the
ED3. The resultthen is a line pushed into the scrollback that shouldn't be there.
This PR tries to avoid that situation by forcing the renderer to
flush before the
ED3sequence is sent.References
The
clsandClear-Hostshims were originally added in PR #5627.PR Checklist
checked, I'm ready to accept this work might be rejected in favor of a
different grand plan. Issue number where discussion took place: #xxx
Validation Steps Performed
I've manually tested in PowerShell with
echo Hello; Clear-Host(thisis the only way I could reliably reproduce the original problem), and in
the cmd shell with
cls. Both cases are now working as expected.