Literally one pixel beyond the edges of the window. I've attached a screenshot that I hope illustrates this.
You see two windows which were auto-placed by the window manager. If they didn't have scroll bars, they wouldn't overlap, but they do, by one pixel. Depending on which window is in the foreground, the rightmost pixel of the scroll bar is either below or above the other window.
The bottommost pixel of the scroll bar extending below the window is evident in both cases.
Literally one pixel beyond the edges of the window. I've attached a screenshot that I hope illustrates this.
You see two windows which were auto-placed by the window manager. If they didn't have scroll bars, they wouldn't overlap, but they do, by one pixel. Depending on which window is in the foreground, the rightmost pixel of the scroll bar is either below or above the other window.
The bottommost pixel of the scroll bar extending below the window is evident in both cases.