amount = 1 [See also track mouse which shares this code. This command is distinguished by having only one parameter and having the first parameter != 0]
Inserts amount lines at the top of the scroll region shifting down the existing lines. Lines at the bottom of the scrolling region are lost.
In left and right margin mode the margins are respected; lines are only scrolled in the scroll region.
If the cell movement splits a multi cell character that character is cleared, by replacing it by spaces, keeping its current attributes.
The new lines are created according to the current SGR state
Does not change the (absolute) cursor position.
amount is 0 adjusts it to 1.🛈 Before version 21.12.0, when scrolling the full scrolling region size the last line is not scrolled out.
🛆 if amount is 0 adjusts it to 1.