Move the cursor to the previous line in the scrolling region, possibly scrolling.
If the cursor is outside of the scrolling region:
- move the cursor one line up if it is not on the top-most line of the screen.
If the cursor is inside the scrolling region:
- If the cursor is on the top-most line of the scrolling region:
- If the cursor is not on the top-most line of the scrolling region:
- move the cursor one line up
This unsets the pending wrap state without wrapping.