Add command to recenter errors from Occur/Grep buffers

To scroll up/down the current displayed occurrence/error
without abandon the Occur/Grep buffer.

Add also a command 'recenter-other-window' to recenter
the other window from any kind of buffer.

* lisp/window.el (recenter-other-window): New command.
Bind recenter-other-window to S-M-C-l (Bug#46119).

* lisp/simple.el (recenter-current-error): New command.
* lisp/progmodes/grep.el (grep-mode-map):
Delete bidings for n and p.

* lisp/progmodes/compile.el (compilation-minor-mode-map):
Move here the n and p bindings.
Bind `recenter-current-error' to l.
* lisp/replace.el (occur-mode-map):
Same.

* doc/emacs/windows.texi (Other Window):
* doc/emacs/display.texi (Recentering):
Document recenter-other-window.

* etc/NEWS (Changes in Specialized Modes and Packages in Emacs 28.1):
Announce the changes.

doc/emacs/display.texi

@@ -173,6 +173,10 @@ line; on subsequent consecutive invocations, make the current line the
 top line, the bottom line, and so on in cyclic order.  Possibly
 redisplay the screen too (@code{recenter-top-bottom}).
 
+@item C-M-S-l
+Scroll the other window; this is equivalent to @kbd{C-l} acting on the
+other window.
+
 @item M-x recenter
 Scroll the selected window so the current line is the center-most text
 line.  Possibly redisplay the screen too.

doc/emacs/windows.texi

@@ -161,6 +161,8 @@ Select another window (@code{other-window}).
 Scroll the next window upward (@code{scroll-other-window}).
 @item C-M-S-v
 Scroll the next window downward (@code{scroll-other-window-down}).
+@item C-M-S-l
+Recenter the next window (@code{recenter-other-window}).
 @item mouse-1
 @kbd{mouse-1}, in the text area of a window, selects the window and
 moves point to the position clicked.  Clicking in the mode line
@@ -194,6 +196,8 @@ rebind a command.)
 @findex scroll-other-window
 @kindex C-M-S-v
 @findex scroll-other-window-down
+@kindex C-M-S-l
+@findex recenter-other-window
   The usual scrolling commands (@pxref{Display}) apply to the selected
 window only, but there are also commands to scroll the next window.
 @kbd{C-M-v} (@code{scroll-other-window}) scrolls the window that
@@ -203,7 +207,9 @@ take positive and negative arguments.  (In the minibuffer, @kbd{C-M-v}
 scrolls the help window associated with the minibuffer, if any, rather
 than the next window in the standard cyclic order; @pxref{Minibuffer
 Edit}.)  @kbd{C-M-S-v} (@code{scroll-other-window-down}) scrolls the
-next window downward in a similar way.
+next window downward in a similar way.  Likewise, @kbd{C-M-S-l}
+(@code{recenter-other-window}) behaves like @kbd{C-l}
+(@code{recenter-top-bottom}) in the next window.
 
 @vindex mouse-autoselect-window
   If you set @code{mouse-autoselect-window} to a non-@code{nil} value,

etc/NEWS

@@ -85,7 +85,11 @@ useful on systems such as FreeBSD which ships only with "etc/termcap".
 
 * Changes in Emacs 28.1
 
-** The new NonGNU ELPA archive is enabled by default alongside GNU ELPA.
++++
+** New command 'recenter-other-window', bound to 'S-M-C-l'.
+Like 'recenter-top-bottom' acting in the other window.
+
+** The new NonGNU ELPA archive is enabled by default alongside GNU ELPA
 
 ** Minibuffer scrolling is now conservative by default.
 This is controlled by the new variable 'scroll-minibuffer-conservatively'.
@@ -469,9 +473,14 @@ applied when the option 'tab-line-tab-face-functions' is
 so-configured.  That option may also be used to customize tab-line
 faces in other ways.
 
-** New bindings in occur-mode, 'next-error-no-select' bound to 'n' and
+** Occur mode
+
+*** New bindings in occur-mode, 'next-error-no-select' bound to 'n' and
 'previous-error-no-select' bound to 'p'.
 
+*** The new command 'recenter-current-error', bound to 'l' in Occur or
+compilation buffers, recenters the current displayed occurrence/error.
+
 ** EIEIO
 
 +++

lisp/progmodes/compile.el

@@ -2069,6 +2069,10 @@ Returns the compilation buffer created."
     (define-key map "\M-p" 'compilation-previous-error)
     (define-key map "\M-{" 'compilation-previous-file)
     (define-key map "\M-}" 'compilation-next-file)
+    (define-key map "n" 'next-error-no-select)
+    (define-key map "p" 'previous-error-no-select)
+    (define-key map "l" 'recenter-current-error)
+
     (define-key map "g" 'recompile) ; revert
     ;; Set up the menu-bar
     (define-key map [menu-bar compilation]

lisp/progmodes/grep.el

@@ -275,8 +275,6 @@ See `compilation-error-screen-columns'."
     (define-key map "\C-c\C-f" 'next-error-follow-minor-mode)
 
     (define-key map "\r" 'compile-goto-error)  ;; ?
-    (define-key map "n" 'next-error-no-select)
-    (define-key map "p" 'previous-error-no-select)
     (define-key map "{" 'compilation-previous-file)
     (define-key map "}" 'compilation-next-file)
     (define-key map "\t" 'compilation-next-error)

lisp/replace.el

@@ -1161,6 +1161,7 @@ a previously found match."
     (define-key map "\C-o" 'occur-mode-display-occurrence)
     (define-key map "n" 'next-error-no-select)
     (define-key map "p" 'previous-error-no-select)
+    (define-key map "l" 'recenter-current-error)
     (define-key map "\M-n" 'occur-next)
     (define-key map "\M-p" 'occur-prev)
     (define-key map "r" 'occur-rename-buffer)

lisp/simple.el

@@ -492,6 +492,16 @@ buffer causes automatic display of the corresponding source code location."
         (overlay-put ol 'window (get-buffer-window))
         (setf next-error--message-highlight-overlay ol)))))
 
+(defun recenter-current-error (&optional arg)
+  "Recenter the current displayed error in the `next-error' buffer."
+  (interactive "P")
+  (save-selected-window
+    (let ((next-error-highlight next-error-highlight-no-select)
+          (display-buffer-overriding-action
+           '(nil (inhibit-same-window . t))))
+      (next-error 0)
+      (set-buffer (window-buffer))
+      (recenter-top-bottom arg))))
 
 ;;;
 

lisp/window.el

@@ -9768,6 +9768,19 @@ With plain \\[universal-argument], move current line to window center."
 
 (define-key global-map [?\C-l] 'recenter-top-bottom)
 
+(defun recenter-other-window (&optional arg)
+  "Call `recenter-top-bottom' in the other window.
+
+A prefix argument is handled like `recenter':
+ With numeric prefix ARG, move current line to window-line ARG.
+ With plain `C-u', move current line to window center."
+  (interactive "P")
+  (with-selected-window (other-window-for-scrolling)
+    (recenter-top-bottom arg)
+    (pulse-momentary-highlight-one-line (point))))
+
+(define-key global-map [?\S-\M-\C-l] 'recenter-other-window)
+
 (defun move-to-window-line-top-bottom (&optional arg)
   "Position point relative to window.