New 0.11 VT attributes bug, attributes are not applied to " " (space) cells #8093

Open
opened 2026-01-31 01:20:37 +00:00 by claunia · 0 comments
Owner

Originally created by @PhMajerus on GitHub (May 12, 2020).

In Windows Terminal 0.11.1251.0, a new VT attributes bug has been introduced.

When output contains VT escape sequences to set text attributes, they are sometimes ignored when the cells contains the space character.

If this sounds a lot like #5502, it is because it's probably exactly the same issue, you need to write spaces not only when the background color is different, but also if some other attributes, such underline are set (and you probably should make sure you include reverse video and crossed-out as well).

Repro command line : curl 'https://raw.githubusercontent.com/PhMajerus/ANSI-art/master/Windows%20Terminal.ans' | sed 'H;$!d;x;s/\x1A.*$//' | iconv -f CP437

image

Compare the top of the "W" with conhost:
image

It seems to be a bit random, even when it's not scrolling the buffer:
image

File used: https://github.com/PhMajerus/ANSI-art/blob/master/Windows%20Terminal.ans

Originally created by @PhMajerus on GitHub (May 12, 2020). In Windows Terminal 0.11.1251.0, a new VT attributes bug has been introduced. When output contains VT escape sequences to set text attributes, they are sometimes ignored when the cells contains the space character. If this sounds a lot like #5502, it is because it's probably exactly the same issue, you need to write spaces not only when the background color is different, but also if some other attributes, such underline are set (and you probably should make sure you include reverse video and crossed-out as well). Repro command line : `curl 'https://raw.githubusercontent.com/PhMajerus/ANSI-art/master/Windows%20Terminal.ans' | sed 'H;$!d;x;s/\x1A.*$//' | iconv -f CP437` ![image](https://user-images.githubusercontent.com/25664275/81724825-4b1d6400-9485-11ea-9f03-41098f687663.png) Compare the top of the "W" with conhost: ![image](https://user-images.githubusercontent.com/25664275/81724934-72743100-9485-11ea-91d8-6e8797578698.png) It seems to be a bit random, even when it's not scrolling the buffer: ![image](https://user-images.githubusercontent.com/25664275/81725053-946db380-9485-11ea-8df3-d09c9468054c.png) File used: https://github.com/PhMajerus/ANSI-art/blob/master/Windows%20Terminal.ans
Sign in to join this conversation.
1 Participants
Notifications
Due Date
No due date set.
Dependencies

No dependencies set.

Reference: starred/terminal#8093