Fix copying wrapped lines by implementing better scrolling #5181

zadjii-msft · 2020-03-30T17:39:53Z

Now that the Terminal is doing a better job of actually marking which
lines were and were not wrapped, we're not always copying lines as
"wrapped" when they should be. We're more correctly marking lines as not
wrapped, when previously we'd leave them marked wrapped.

The real problem is here in the ScrollFrame method - we'd manually
newline the cursor to make the terminal's viewport shift down to a new
line. If we had to scroll the viewport for a wrapped line, this would
cause the Terminal to mark that line as broken, because conpty would
emit an extra \n that didn't actually exist.

This more correctly implements ScrollFrame. Now, well move where we
"thought" the cursor was, so when we get to the next PaintBufferLine,
if the cursor needs to newline for the next line, it'll newline, but if
we're in the middle of a wrapped line, we'll just keep printing the
wrapped line.

A couple follow up bugs were found to be caused by the same bad logic.
See #5039 and #5161 for more details on the investigations there.

References

Add support for "reflow"ing the Terminal buffer #4741 RwR, which probably made this worse
Correct scrolling invalidation region for tmux in pty w/ bitmap #5122, which I branched off of
linewrap then backspace produces unexpected visuals, missing characters #1245, One cell at the right end of the screen is ignored #357 - a pair of other conpty wrapped lines bugs
Conpty: Additional ScrollFrame optimizations #5228 - A followup issue for this PR

PR Checklist

Closes Terminal breaks copied text at window line wraps, even when the text has no new-line characters #5113
Closes Neovim Cursor Flickers from Block to Bar running in MS Terminal under Tmux #5180 (by fixing DECRST 25)
Closes Clear-Host fails to clear the first line #5039
Closes Scrolling down in VIM scrolls up duplicated vim status lines #5161 (by ensuring we only removeSpaces on the actual
bottom line)
I work here
Tests added/passed
[n/a] Requires documentation to be updated

Validation Steps Performed

Checked the cases from linewrap then backspace produces unexpected visuals, missing characters #1245, One cell at the right end of the screen is ignored #357 to validate that they still work
Added more and more tests for these scenarios, and then I added MORE
tests
The entire team played with this in selfhost builds

…idation within AdjustCursorPosition routine in the subsection about scrolling down at the bottom with a set of margins enabled.

…g to ETW. Change the scroll member variable to a til::point and math that directly (and add the operators and related tests to til::point).

(cherry picked from commit d972b5e)

…migrie/b/5113-with-miniksas-fix # Conflicts: # src/renderer/vt/XtermEngine.cpp # src/renderer/vt/invalidate.cpp

The test fails validating the second wrapped terminal line. I think the problem comes from us manually placing the cursor on the last line of the buffer. When we write the next 20 'A's, the first one gets written on the last cell of the first row, and that's bad. I'm going to see if I can't get rid of that call (the MoveCursor in PaintCursor) for this case. That seems like the cause of all this mess.

TODO: This proves that the scrolling during a frame with other text breaks this scenario. We're going to try and special-case the scrolling thing to _only_ when * the invalid area is the bottom line, and * the line wrapped So in that case, we'll be sure that the next text will cause us to move the viewport down a line appropriately I've got a crazy theory that rendering bottom-up _might_ fix this

…ith-miniksas-fix

# Conflicts: # src/cascadia/UnitTests_TerminalCore/ConptyRoundtripTests.cpp # src/host/ut_host/ConptyOutputTests.cpp # src/renderer/vt/XtermEngine.cpp # src/renderer/vt/math.cpp

It was unhappy with the exact line lengths and this change

DHowett-MSFT · 2020-03-30T18:07:00Z

src/renderer/vt/XtermEngine.cpp

@@ -105,7 +105,7 @@ XtermEngine::XtermEngine(_In_ wil::unique_hfile hPipe,
        // by prepending a cursor off.
        if (_lastCursorIsVisible)
        {
-            _buffer.insert(0, "\x1b[25l");
+            _buffer.insert(0, "\x1b[?25l");


.. lol, how long has this been like this, and does it map to any bugs in our repo?

and is there a constant val we can use somewhere

It was mentioned in #3093, and I had a branch that fixed this before (dev/migrie/b/be-better-at-hiding), but I have no memory of why that was never fixed

src/renderer/vt/tracing.cpp

DHowett-MSFT · 2020-03-30T18:11:05Z

src/renderer/vt/XtermEngine.cpp

+    // position we think we left the cursor.
+    //
+    // See GH#5113
+    _lastText.Y += dy;


with the newlining gone, how do we make sure that the pty host knows how many lines got pushed?

explicit in the comment that was removed, too, is the pushing-into-scrollback behavior

wait could you clarify? maybe it's just 5 o'clock calling, but I can't make sense of this comment 🙃

Oh. This function used to print a set of newlines commensurate with the scroll distance, which would make the connected terminal push the scrolled-off lines into its scrollback. The newlines are now dead, and I can't determine whether that broke anything.

They seemingly didn't break anything.

Conpty always emits a frame immediately before every new line, due to TriggerCircling. Basically we'll finish printing the frame before the newline, then we'll additionally paint another frame with scrollDelta={0, -1}, and in that second frame, since the cursor is now one line higher, we'll newline to move the cursor down, into the new line in the terminal.

Since we're emitting a frame every newline, I'm not sure this function can actually get called with a delta != 1

src/renderer/vt/XtermEngine.cpp

DHowett · 2020-04-01T06:59:36Z

Testing a selfhost build with this in it, I am seeing terminal not responding to ?25h. I don't know if this is caused by this PR :) I just haven't done a bisect and wanted to make sure I didn't lose it

zadjii-msft · 2020-04-01T13:44:39Z

Testing a selfhost build with this in it, I am seeing terminal not responding to ?25h. I don't know if this is caused by this PR :) I just haven't done a bisect and wanted to make sure I didn't lose it

Can I get an exact repro to investigate? If what you're seeing is in 0.11.912.0, I'm not seeing that with a simple

printf '\e[?25l'
printf '\e[?25h'

in bash

src/host/ut_host/ConptyOutputTests.cpp

src/cascadia/UnitTests_TerminalCore/ConptyRoundtripTests.cpp

DHowett-MSFT · 2020-04-01T18:48:37Z

OKAY, here's your repro.

^[[?25l^[[H^[[115CXXXXX^[[4;9H^[[?25h

terminal size 120-wide (required)
cursor off
home the cursor
write up against the right edge of the screen (X=115, W=120, string="XXXXX")
move the cursor again
cursor back on

If this arrives in one packet, the cursor will remain hidden.

DHowett-MSFT · 2020-04-01T18:51:48Z

What comes out of the debug tap:

␛[?25l␛[1;76HXXXXX␛[?25h

it seems like the cursor becomes visible, in delayed-EOL position off the edge. conpty doesn't render out the next cursor movement because no text comes with it. Here it says 76 because my terminal was 80, not 120.

.github/actions/spell-check/patterns/patterns.txt

DHowett-MSFT

Seems sane and reasonable to me. The newest fixes haven't invalidated the earlier ones, right?

DHowett-MSFT · 2020-04-08T18:46:47Z

src/renderer/vt/paint.cpp

@@ -558,7 +555,7 @@ using namespace Microsoft::Console::Types;
        {
            _deferredCursorPos = { _lastText.X + sNumSpaces, _lastText.Y };
        }
-        else if (numSpaces > 0)
+        else if (removeSpaces && numSpaces > 0)


If we're removing spaces, and there were spaces, print them? I am confus

Man so am I, I have no idea why that fixed the test and didn't break any of the other ones. It was literally the first thing I guessed, looks like I didn't actually add a comment

DHowett-MSFT · 2020-04-08T20:00:55Z

src/renderer/vt/paint.cpp

@@ -538,15 +547,15 @@ using namespace Microsoft::Console::Types;
            RETURN_IF_FAILED(_EraseLine());
        }
    }
-    else if (_newBottomLine)
+    else if (_newBottomLine && coord.Y == _lastViewport.BottomInclusive())


oh it was the same issue as before! should we pull this out into a local, dirtyingNewBottomLine? That'll make sure we don't use _newBottomLine as much in the body here..

Eh probably

DHowett-MSFT · 2020-04-09T00:01:01Z

@msftbot merge this in 5 minutes

ghost · 2020-04-09T00:01:04Z

Hello @DHowett-MSFT!

Because you've given me some instructions on how to help merge this pull request, I'll be modifying my merge approach. Here's how I understand your requirements for merging this pull request:

I won't merge this pull request until after the UTC date Thu, 09 Apr 2020 00:06:03 GMT, which is in 5 minutes

If this doesn't seem right to you, you can tell me to cancel these instructions and use the auto-merge policy that has been configured for this repository. Try telling me "forget everything I just told you".

## Summary of the Pull Request When WSL vim prints the initial empty buffer (the one that's just a bunch of '\~'s), it prints this by doing the following: * Print '\~' followed by enough spaces to clear the line * Use CUP (`^[[H`) to move the cursor to the start of the next line * repeat until the buffer is full When we'd get the line of "\~ "... in conhost, we'd mark that line as wrapped. Logically, it doesn't really make any sense that when we follow that up by moving the cursor, the line is wrapped. However, this is just how conhost is right now. This wasn't ever a problem in just conhost before, because we really didn't care if lines in the alt buffer were "wrapped" or not. Plus, when vim would get resized, it would just reprint it's own buffer anyways. Nor was this a problem in conpty before this year (2020). We've only just recently added logic to conpty to try and preserve wrapped lines. Initially, I tried fixing this by breaking the line manually when the cursor was moved. This seemed to work great, except for the win32 vim.exe. Vim.exe doesn't emit a newline or a CUP to get to the next line. It just _goes for it_ and keeps printing. So there's _no way_ for us to know the line broke, because they're essentially just printing one long line, assuming we'll automatically move the cursor. So instead, I'm making sure to emit the proper number of spaces at the end of a line when the line is wrapped. We won't do any funny business in that scenario and try to optimize for them, we'll _just print the spaces_. ## References * #5181 - This change regressed this * #4415 - Actually implemented wrapped lines in conpty ## PR Checklist * [x] Closes #5291 * [x] I work here * [x] Tests added/passed * [n/a] Requires documentation to be updated ## Validation Steps Performed * Wrote a unittest first and foremost * Checked vtpipeterm to make sure vim still works * checked Terminal to make sure vim still works

Improve wide glyph support in UIA (GH-4946) Add enhanced key support for ConPty (GH-5021) Set DxRenderer non-text alias mode (GH-5149) Reduce CursorChanged Events for Accessibility (GH-5196) Add more object ID tracing for Accessibility (GH-5215) Add SS3 cursor key encoding to ConPty (GH-5383) UIA: Prevent crash from invalid UTR endpoint comparison (GH-5399) Make CodepointWidthDetector::GetWidth faster (CC-3727) add til::math, use it for float conversions to point, size (GH-5150) Add support for renderer backoff, don't FAIL_FAST on 3x failures, add UI (GH-5353) Fix a deadlock and a bounding rects issue in UIA (GH-5385) Don't duplicate spaces from potentially-wrapped EOL-deferred lines (GH-5398) Reimplement the VT tab stop functionality (CC-5173) Clamp parameter values to a maximum of 32767. (CC-5200) Prevent the cursor type being reset when changing the visibility (CC-5251) Make RIS switch back to the main buffer (CC-5248) Add support for the DSR-OS operating status report (CC-5300) Update the virtual bottom location if the cursor moves below it (CC-5317) ci: run spell check in CI, fix remaining issues (CC-4799) (CC-5352) Set Cascadia Code as default font (GH-5121) Show a double width cursor for double width characters (GH-5319) Delegate all character input to the character event handler (CC-4192) Update til::bitmap to use dynamic_bitset<> + libpopcnt (GH-5092) Merged PR 4465022: [Git2Git] Merged PR 4464559: Console: Ingest OSS changes up to e055079 Correct scrolling invalidation region for tmux in pty w/ bitmap (GH-5122) Render row-by-row instead of invalidating entire screen (GH-5185) Make conechokey use ReadConsoleInputW by default (GH-5148) Manually pass mouse wheel messages to TermControls (GH-5131) This fixes C-M-space for WSL but not for Win32, but I'm not sure there's a problem in Win32 quite yet. (GH-5208) Fix copying wrapped lines by implementing better scrolling (GH-5181) Emit lines wrapped due to spaces at the end correctly (GH-5294) Remove unneeded whitespace (CC-5162)

ghost · 2020-04-22T17:14:03Z

🎉Windows Terminal Preview v0.11.1121.0 has been released which incorporates this pull request.:tada:

Handy links:

## Summary of the Pull Request The dirty view calculation in the `XtermEngine::StartPaint` method was originally used to detect a full frame paint that would require a clear screen, but that code was removed as part of PR #4741, making this calculation obsolete. The `performedSoftWrap` variable in the `XtermEngine::_MoveCursor` method was assumedly a remanent of some WIP code that was mistakenly committed in PR #5181. The variable was never actually used. ## Validation Steps Performed All the unit tests still pass and nothing seems obviously broken in manual testing. ## PR Checklist - [x] Closes #17280

miniksa and others added 17 commits March 25, 2020 14:29

Add tracing for circling and scrolling operations. Fix improper inval…

4bbb63d

…idation within AdjustCursorPosition routine in the subsection about scrolling down at the bottom with a set of margins enabled.

PR feedback applied. Don't bother making string if no one is listenin…

a543b1f

…g to ETW. Change the scroll member variable to a til::point and math that directly (and add the operators and related tests to til::point).

More tracing is always good

9ba2c69

(cherry picked from commit d972b5e)

Merge remote-tracking branch 'origin/dev/miniksa/tmux_draw' into dev/…

f10edc0

…migrie/b/5113-with-miniksas-fix # Conflicts: # src/renderer/vt/XtermEngine.cpp # src/renderer/vt/invalidate.cpp

So this works but I think it will break the EOL backspace test

d42f960

This can't possibly be right... can it?

22bdf9b

mysteriously the existing tests all basically pass

466e8fc

this is a simple test for the case that already worked

248d223

This all wroks far to shockingly well

e21101b

this fixes this test, but maybe the test was always broken?

2665b4c

I'm honestly shocked that this seems to work

2a0cc20

Merge remote-tracking branch 'origin/master' into dev/migrie/b/5113-w…

870f052

…ith-miniksas-fix

cleanup for review, but I have to wait for #5122 to merge first

51f060e

Merge branch 'master' into dev/migrie/b/5113-with-miniksas-fix

8ecfcec

# Conflicts: # src/cascadia/UnitTests_TerminalCore/ConptyRoundtripTests.cpp # src/host/ut_host/ConptyOutputTests.cpp # src/renderer/vt/XtermEngine.cpp # src/renderer/vt/math.cpp

Fix the test @miniksa wrote for #5122

436335f

It was unhappy with the exact line lengths and this change

zadjii-msft added the Product-Conpty For console issues specifically related to conpty label Mar 30, 2020

DHowett-MSFT reviewed Mar 30, 2020

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src/renderer/vt/XtermEngine.cpp Show resolved Hide resolved

This was referenced Mar 31, 2020

Neovim Cursor Flickers from Block to Bar running in MS Terminal under Tmux #5180

Closed

Clear-Host fails to clear the first line #5039

Closed

zadjii-msft mentioned this pull request Apr 1, 2020

Feature request: Add redundant \r on line wrap #5202

Closed

Merge branch 'master' into dev/migrie/b/5113-with-miniksas-fix

022b01a

pr nits from dustin

ac85d43

carlos-zamora reviewed Apr 1, 2020

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src/host/ut_host/ConptyOutputTests.cpp Outdated Show resolved Hide resolved

src/cascadia/UnitTests_TerminalCore/ConptyRoundtripTests.cpp Outdated Show resolved Hide resolved

zadjii-msft added 2 commits April 8, 2020 10:23

some PR feedback

1cc1035

I guess I need this one too

c111961

jsoref reviewed Apr 8, 2020

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.github/actions/spell-check/patterns/patterns.txt Outdated Show resolved Hide resolved

zadjii-msft added 3 commits April 8, 2020 11:03

Add a test to cover the new case Dustin found

15a47d3

Fix the bug that dustin found. 0% change spellcheck bot loves me

5e167cd

love me

efe4aaf

DHowett-MSFT approved these changes Apr 8, 2020

View reviewed changes

This makes more sense

d5af8c6

DHowett-MSFT reviewed Apr 8, 2020

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ghost added the AutoMerge Marked for automatic merge by the bot when requirements are met label Apr 9, 2020

ghost merged commit 6fabc4a into master Apr 9, 2020

ghost deleted the dev/migrie/b/5113-with-miniksas-fix branch April 9, 2020 00:06

This was referenced Apr 9, 2020

Emit lines wrapped due to spaces at the end correctly #5294

Merged

Horizontal Pane Splitting puts cursor on incorrect line #5295

Closed

skyline75489 mentioned this pull request Apr 13, 2020

When copying wrapped text, occasionally copies rendered newline #5332

Closed

skyline75489 mentioned this pull request Apr 17, 2020

The copyed text is splited into multiple line #5390

Closed

zadjii-msft mentioned this pull request Apr 17, 2020

The copyed text is splited into multiple line #5389

Closed

miniksa mentioned this pull request Apr 20, 2020

Adjusts High DPI scaling to enable differential rendering #5345

Merged

9 tasks

zadjii-msft mentioned this pull request Apr 20, 2020

Decreasing the width of vim.exe corrupts buffer #5428

Closed

zadjii-msft mentioned this pull request May 12, 2020

[Scenario] 2 Resize 2 Reflow #5800

Open

31 tasks

j4james mentioned this pull request Jul 31, 2021

SM ? 25h by conhost is paired wrongly with a SM 25 l (missing ?) #10829

Closed

zadjii-msft mentioned this pull request Dec 7, 2022

Text Wrapping with ConPTY #405

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This was referenced May 16, 2024

Unused/obsolete code in XtermEngine #17280

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Remove some unused/obsolete XtermEngine code #17287

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Fix copying wrapped lines by implementing better scrolling #5181

Fix copying wrapped lines by implementing better scrolling #5181

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edited by DHowett-MSFT

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Fix copying wrapped lines by implementing better scrolling #5181

Fix copying wrapped lines by implementing better scrolling #5181

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References

PR Checklist

Validation Steps Performed

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