Replace GROUP argument in six window primitives by new functions.

* doc/lispref/windows.texi (Window Start and End, Textual Scrolling)
* doc/lispref/positions.texi (Screen Lines): Remove optional GROUP argument
from description of six window functions.  Add in description of new functions
window-group-start, window-group-end, set-window-group-start,
pos-visible-in-window-group-p, recenter-group and move-to-window-group-line,
together with the six variables indirecting to the pertinent group
functions.

* src/window.c
* src/keyboard.c: Revert the commit from 2015-11-11 12:02:48, in so far as it
applies to these two files, which added the GROUP argument to six window
primitives.

* lisp/follow.el (follow-mode): Use updated variable names for the indirected
functions.

* lisp/isearch.el (isearch-update, isearch-done, isearch-string-out-of-window)
(isearch-back-into-window, isearch-lazy-highlight-new-loop)
(isearch-lazy-highlight-search, isearch-lazy-highlight-update): Replace calls
to window primitives (e.g. window-start) with a GROUP argument by calls to
new functions (e.g. window-group-start).

* lisp/ispell.el (ispell-command-loop): Replace call to
pos-visible-in-window-p with pos-visible-in-window-group-p.

* lisp/window.el (window-group-start, window-group-end)
(set-window-group-start, recenter-group, pos-visible-in-window-group-p)
(selected-window-group, move-to-window-group-line): New functions.
(window-group-start-function, window-group-end-function)
(set-window-group-start-function, recenter-group-function)
(pos-visible-in-window-group-p-function, selected-window-group-function)
(move-to-window-group-line-function): New variables.

1 files changed, 14 insertions, 12 deletions

diff --git a/doc/lispref/positions.texi b/doc/lispref/positions.texi
index e0496e30848..090eb4598a8 100644
--- a/doc/lispref/positions.texi
+++ b/doc/lispref/positions.texi
@@ -551,8 +551,7 @@ current buffer, regardless of which buffer is displayed in
 any buffer, whether or not it is currently displayed in some window.
 @end defun
 
-@deffn Command move-to-window-line count group
-@vindex move-to-window-line-group-function
+@deffn Command move-to-window-line count
 This function moves point with respect to the text currently displayed
 in the selected window.  It moves point to the beginning of the screen
 line @var{count} screen lines from the top of the window.  If
@@ -571,18 +570,21 @@ In an interactive call, @var{count} is the numeric prefix argument.
 
 The value returned is the window line number point has moved to, with
 the top line in the window numbered 0.
-
-If @var{group} is non-@code{nil}, and the selected window is a part of
-a group of windows (@pxref{Basic Windows}), @code{move-to-window-line}
-will move to a position with respect to the entire group, not just the
-single window.  This condition holds when the buffer local variable
-@code{move-to-window-line-group-function} is set to a function.  In
-this case, @code{move-to-window-line} calls the function with the
-argument @var{count}, then returns its result, instead of performing
-the actions described above.  Typically, the function will call
-@code{move-to-window-line} recursively.
 @end deffn
 
+@vindex move-to-window-group-line-function
+@defun move-to-window-group-line count
+This function is like @code{move-to-window-line}, except that when the
+selected window is a part of a group of windows (@pxref{Basic
+Windows}), @code{move-to-window-group-line} will move to a position
+with respect to the entire group, not just the single window.  This
+condition holds when the buffer local variable
+@code{move-to-window-group-line-function} is set to a function.  In
+this case, @code{move-to-window-group-line} calls the function with
+the argument @var{count}, then returns its result.  The argument has
+the same meaning as in @code{move-to-window-line}.
+@end defun
+
 @defun compute-motion from frompos to topos width offsets window
 This function scans the current buffer, calculating screen positions.
 It scans the buffer forward from position @var{from}, assuming that is