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Double-cell characters that get wrapped to the next line not removed from the screen when deleting #2984
Description
Prerequisites
- Write a descriptive title.
- Make sure you are able to repro it on the latest released version
- Search the existing issues, especially the pinned issues.
Exception report
No exception.Screenshot
Environment data
PS Version: 7.2.0-rc.1
PS HostName: ConsoleHost (Windows Terminal)
PSReadLine Version: 2.1.0
PSReadLine EditMode: Windows
OS: 10.0.19041.1 (WinBuild.160101.0800)
BufferWidth: 91
BufferHeight: 25Steps to reproduce
- Make sure the double-cell character wraps to the next line. It means that there is 1 cell buffer left on the current line for the double-cell character, so that character will be rendered to the next line.
- Start to delete characters, from the end, or from the middle of the line.
- You will see the double-cell character left behinds even though it's already removed from the buffer.
The GIF's in the screenshot section above are 2 examples.
Expected behavior
Deletion works as expected to remove the character from screen.
Actual behavior
The double-cell characters are left on screen, even though the characters were already removed from the text buffer.
Activity
daxian-dbw commentedon Nov 9, 2021
The root cause of this issue is how we calculate the physical line count and the length of the last physical line for a logical line (see code here). The
columnsis the total buffer cells of the logical line (see code here), but it doesn't count into the possibility of the word warping for a double-cell character, which will make the logical line take up more cells than the calculated sum. This causes the line clearing to not work correctly in this case.[-]double-cell characters that get wrapped to the next line not removed from the screen when deleting[/-][+]Double-cell characters that get wrapped to the next line not removed from the screen when deleting[/+]iSazonov commentedon Nov 10, 2021
Intersting, it seems pwsh has such wrapper too. Makes sense to have the code duplicate? I remember we fixed issues in pwsh wrapper code too. Maybe has one well-tested?
daxian-dbw commentedon Nov 10, 2021
I think the "wrapper" code you refer to is for word wrapping. It's different, here is the character wrapping that is done by the terminal/console, not the word wrapping.
iSazonov commentedon Nov 10, 2021
Isn't this based on the "same" helper method to calculate cell width?
daxian-dbw commentedon Nov 10, 2021
I don't know, never really looked at the word wrapping code in PS :)
iSazonov commentedon Nov 10, 2021
It doesn't cover all cases (use a workaround for simplicity). I think it could be good request for new API in .Net Runtime.