employ heuristics in choosing or creating a window; use these functions
when you need complete control.
-@defun set-window-buffer window buffer-or-name
+@defun set-window-buffer window buffer-or-name &optional keep-margins
This function makes @var{window} display @var{buffer-or-name} as its
contents. It returns @code{nil}. This is the fundamental primitive
for changing which buffer is displayed in a window, and all ways
@result{} nil
@end group
@end example
+
+Normally, displaying @var{buffer} in @var{window} resets the window's
+fringe widths and position based on the local variables of @var{buffer}.
+However, if @var{keep-margins} is non-@code{nil}, the fringe widths and
+position of @var{window} remain unchanged. @xref{Fringes}.
@end defun
@defun window-buffer &optional window