ANSI control sequence ESC M uses incorrect default background color (Windows Console Host)

[12Me21]

Environment

Microsoft Windows [Version 10.0.18362.535]

Steps to reproduce

Screen background is set to any color other than 0:

From bash in WSL:

clear
echo -e "\e[H\e[1T"

The control sequence ESC [ 1 T scrolls down 1 line, and fills the new line with the background color

clear
echo -e "\e[H\eM"

The control sequence ESC M also scrolls down 1 line, but uses color 0 instead of the background color

Applications like less, man, and vim all use ESC M for scrolling, and scrolling upwards causes new lines to be filled with the wrong background color:

ESC [ L (insert lines) appears to have the same problem.

Additionally, this only happens when the current background color is set to the default. otherwise, ESC M acts correctly (try inserting \e[41m after the H in the command)

Expected behavior

Both control sequences should have the same behavior

Actual behavior

ESC M uses color 0 instead of the default color, when the background color is set to the default

[j4james]

I believe this was fixed by PR #2987.

[zadjii-msft]

This sure does look like that bug to me as well. Thanks for finding the dupe @j4james!

/dup #2702

[ghost]

Hi! We've identified this issue as a duplicate of another one that already exists on this Issue Tracker. This specific instance is being closed in favor of tracking the concern over on the referenced thread. Thanks for your report!