Allow scrolling in y-or-n-p.

* lisp/replace.el (query-replace-map): Bind four new symbols for
requesting window scrolling.

* lisp/subr.el (y-or-n-p): Handle the window-scrolling bindings in
query-replace-map.

* lisp/custom.el (custom-theme-load-confirm): Use y-or-n-p.

* lisp/window.el (scroll-other-window-down): Make the arg optional.

* lisp/emacs-lisp/map-ynp.el (map-y-or-n-p): Don't bind scrolling keys
since they are now in query-replace-map.

* doc/lispref/minibuf.texi (Yes-or-No Queries): Document recentering and
scrolling in y-or-n-p.  Remove gratuitous example.

* doc/lispref/searching.texi (Search and Replace): Document window scrolling
entries in query-replace-map.

Fixes: debbugs:8948

6 files changed, 78 insertions, 58 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index d7f730556ac..8f089af6f5c 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,20 @@
 2012-09-09  Chong Yidong  <cyd@gnu.org>
 
+	* replace.el (query-replace-map): Bind four new symbols for
+	requesting window scrolling.
+
+	* subr.el (y-or-n-p): Handle the window-scrolling bindings in
+	query-replace-map (Bug#8948).
+
+	* custom.el (custom-theme-load-confirm): Use y-or-n-p.
+
+	* emacs-lisp/map-ynp.el (map-y-or-n-p): Don't bind scrolling keys
+	since they are now in query-replace-map.
+
+	* window.el (scroll-other-window-down): Make the arg optional.
+
+2012-09-09  Chong Yidong  <cyd@gnu.org>
+
 	* files.el (hack-local-variables-confirm): Use quit-window to kill
 	the *Local Variables* buffer.
 
diff --git a/lisp/custom.el b/lisp/custom.el
index fb166dd35f7..3eb2895888d 100644
--- a/lisp/custom.el
+++ b/lisp/custom.el
@@ -1223,38 +1223,19 @@ Return t if THEME was successfully loaded, nil otherwise."
   "Query the user about loading a Custom theme that may not be safe.
 The theme should be in the current buffer.  If the user agrees,
 query also about adding HASH to `custom-safe-themes'."
-  (if noninteractive
-      nil
-    (let ((exit-chars '(?y ?n ?\s))
-	  window prompt char)
-      (save-window-excursion
-	(rename-buffer "*Custom Theme*" t)
-	(emacs-lisp-mode)
-	(setq window (display-buffer (current-buffer)))
-	(setq prompt
-	      (format "Loading a theme can run Lisp code.  Really load?%s"
-		      (if (and window
-			       (< (line-number-at-pos (point-max))
-				  (window-body-height)))
-			  " (y or n) "
-			(push ?\C-v exit-chars)
-			"\nType y or n, or C-v to scroll: ")))
-	(goto-char (point-min))
-	(while (null char)
-	  (setq char (read-char-choice prompt exit-chars))
-	  (when (eq char ?\C-v)
-	    (if window
-		(with-selected-window window
-		  (condition-case nil
-		      (scroll-up)
-		    (error (goto-char (point-min))))))
-	    (setq char nil)))
-	(when (memq char '(?\s ?y))
-	  ;; Offer to save to `custom-safe-themes'.
-	  (and (or custom-file user-init-file)
-	       (y-or-n-p "Treat this theme as safe in future sessions? ")
-	       (customize-push-and-save 'custom-safe-themes (list hash)))
-	  t)))))
+  (unless noninteractive
+    (save-window-excursion
+      (rename-buffer "*Custom Theme*" t)
+      (emacs-lisp-mode)
+      (setq window (pop-to-buffer (current-buffer)))
+      (goto-char (point-min))
+      (prog1 (when (y-or-n-p "Loading a theme can run Lisp code.  Really load? ")
+	       ;; Offer to save to `custom-safe-themes'.
+	       (and (or custom-file user-init-file)
+		    (y-or-n-p "Treat this theme as safe in future sessions? ")
+		    (customize-push-and-save 'custom-safe-themes (list hash)))
+	       t)
+	(quit-window)))))
 
 (defun custom-theme-name-valid-p (name)
   "Return t if NAME is a valid name for a Custom theme, nil otherwise.
diff --git a/lisp/emacs-lisp/map-ynp.el b/lisp/emacs-lisp/map-ynp.el
index e7806440bf3..289751f4944 100644
--- a/lisp/emacs-lisp/map-ynp.el
+++ b/lisp/emacs-lisp/map-ynp.el
@@ -123,16 +123,6 @@ Returns the number of actions taken."
 	    map
             (let ((map (make-sparse-keymap)))
               (set-keymap-parent map query-replace-map)
-              (define-key map [?\C-\M-v] 'scroll-other-window)
-              (define-key map [M-next] 'scroll-other-window)
-              (define-key map [?\C-\M-\S-v] 'scroll-other-window-down)
-              (define-key map [M-prior] 'scroll-other-window-down)
-              ;; The above are rather inconvenient, so maybe we should
-              ;; provide the non-other keys for the other-scroll as well.
-              ;; (define-key map [?\C-v] 'scroll-other-window)
-              ;; (define-key map [next] 'scroll-other-window)
-              ;; (define-key map [?\M-v] 'scroll-other-window-down)
-              ;; (define-key map [prior] 'scroll-other-window-down)
               (dolist (elt action-alist)
                 (define-key map (vector (car elt)) (vector (nth 1 elt))))
               map)))
diff --git a/lisp/replace.el b/lisp/replace.el
index 194805a8f3e..b30b671122e 100644
--- a/lisp/replace.el
+++ b/lisp/replace.el
@@ -1617,14 +1617,28 @@ E to edit the replacement string"
     (define-key map "?" 'help)
     (define-key map "\C-g" 'quit)
     (define-key map "\C-]" 'quit)
-    (define-key map "\e" 'exit-prefix)
+    (define-key map "\C-v" 'scroll-up)
+    (define-key map "\M-v" 'scroll-down)
+    (define-key map [next] 'scroll-up)
+    (define-key map [prior] 'scroll-down)
+    (define-key map [?\C-\M-v] 'scroll-other-window)
+    (define-key map [M-next] 'scroll-other-window)
+    (define-key map [?\C-\M-\S-v] 'scroll-other-window-down)
+    (define-key map [M-prior] 'scroll-other-window-down)
+    ;; Binding ESC would prohibit the M-v binding.  Instead, callers
+    ;; should check for ESC specially.
+    ;; (define-key map "\e" 'exit-prefix)
     (define-key map [escape] 'exit-prefix)
     map)
-  "Keymap that defines the responses to questions in `query-replace'.
+  "Keymap of responses to questions posed by commands like `query-replace'.
 The \"bindings\" in this map are not commands; they are answers.
 The valid answers include `act', `skip', `act-and-show',
-`exit', `act-and-exit', `edit', `edit-replacement', `delete-and-edit',
-`recenter', `automatic', `backup', `exit-prefix', `quit', and `help'.")
+`act-and-exit', `exit', `exit-prefix', `recenter', `scroll-up',
+`scroll-down', `scroll-other-window', `scroll-other-window-down',
+`edit', `edit-replacement', `delete-and-edit', `automatic',
+`backup', `quit', and `help'.
+
+This keymap is used by `y-or-n-p' as well as `query-replace'.")
 
 (defvar multi-query-replace-map
   (let ((map (make-sparse-keymap)))
diff --git a/lisp/subr.el b/lisp/subr.el
index 21dd270caef..be785ff8fba 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -2319,11 +2319,19 @@ floating point support."
 PROMPT is the string to display to ask the question.  It should
 end in a space; `y-or-n-p' adds \"(y or n) \" to it.
 
-No confirmation of the answer is requested; a single character is enough.
-Also accepts Space to mean yes, or Delete to mean no.  \(Actually, it uses
-the bindings in `query-replace-map'; see the documentation of that variable
-for more information.  In this case, the useful bindings are `act', `skip',
-`recenter', and `quit'.\)
+No confirmation of the answer is requested; a single character is
+enough.  SPC also means yes, and DEL means no.
+
+To be precise, this function translates user input into responses
+by consulting the bindings in `query-replace-map'; see the
+documentation of that variable for more information.  In this
+case, the useful bindings are `act', `skip', `recenter',
+`scroll-up', `scroll-down', and `quit'.
+An `act' response means yes, and a `skip' response means no.
+A `quit' response means to invoke `keyboard-quit'.
+If the user enters `recenter', `scroll-up', or `scroll-down'
+responses, perform the requested window recentering or scrolling
+and ask again.
 
 Under a windowing system a dialog box will be used if `last-nonmenu-event'
 is nil and `use-dialog-box' is non-nil."
@@ -2355,21 +2363,33 @@ is nil and `use-dialog-box' is non-nil."
                                "" " ")
                            "(y or n) "))
       (while
-          (let* ((key
+          (let* ((scroll-actions '(recenter scroll-up scroll-down
+				   scroll-other-window scroll-other-window-down))
+		 (key
                   (let ((cursor-in-echo-area t))
                     (when minibuffer-auto-raise
                       (raise-frame (window-frame (minibuffer-window))))
-                    (read-key (propertize (if (eq answer 'recenter)
+                    (read-key (propertize (if (memq answer scroll-actions)
                                               prompt
                                             (concat "Please answer y or n.  "
                                                     prompt))
                                           'face 'minibuffer-prompt)))))
             (setq answer (lookup-key query-replace-map (vector key) t))
             (cond
-             ((memq answer '(skip act)) nil)
-             ((eq answer 'recenter) (recenter) t)
-             ((memq answer '(exit-prefix quit)) (signal 'quit nil) t)
-             (t t)))
+	     ((memq answer '(skip act)) nil)
+	     ((eq answer 'recenter)
+	      (recenter) t)
+	     ((eq answer 'scroll-up)
+	      (ignore-errors (scroll-up-command)) t)
+	     ((eq answer 'scroll-down)
+	      (ignore-errors (scroll-down-command)) t)
+	     ((eq answer 'scroll-other-window)
+	      (ignore-errors (scroll-other-window)) t)
+	     ((eq answer 'scroll-other-window-down)
+	      (ignore-errors (scroll-other-window-down)) t)
+	     ((or (memq answer '(exit-prefix quit)) (eq key ?\e))
+	      (signal 'quit nil) t)
+	     (t t)))
         (ding)
         (discard-input))))
     (let ((ret (eq answer 'act)))
diff --git a/lisp/window.el b/lisp/window.el
index b071a8e9c50..dd1f55450c3 100644
--- a/lisp/window.el
+++ b/lisp/window.el
@@ -6301,7 +6301,7 @@ This is different from `scroll-down-command' that scrolls a full screen."
 (put 'scroll-down-line 'scroll-command t)
 
 
-(defun scroll-other-window-down (lines)
+(defun scroll-other-window-down (&optional lines)
   "Scroll the \"other window\" down.
 For more details, see the documentation for `scroll-other-window'."
   (interactive "P")