bug#19064: 25.0.50; `message' overwrites `y-or-n-p' prompt, so user misses it

[Juri Linkov]

>>   Seems like whenever `y-or-n-p' (or just `read-key') is waiting
>>   for a key, `message' should do nothing.  Either it should echo
>>   its message after the key is read or (maybe better) it should
>>   do nothing at all.  As it stands now, this seems like a basic
>>   UI problem, not just a minor annoyance.
>
> I tried this here with emacs 25:
>
> (progn
>   (man "X")
>   (y-or-n-p "-->"))

Here is the patch that fixes this (required changes from bug#38076):

diff --git a/lisp/man.el b/lisp/man.el
index 9d21e953d1..27a134e004 100644
--- a/lisp/man.el
+++ b/lisp/man.el
@@ -1389,7 +1389,7 @@ Man-bgproc-sentinel
   (let ((Man-buffer (if (stringp process) (get-buffer process)
                      (process-buffer process)))
        (delete-buff nil)
-       (err-mess nil))
+        message)
 
     (if (null (buffer-name Man-buffer)) ;; deleted buffer
        (or (stringp process)
@@ -1402,9 +1402,9 @@ Man-bgproc-sentinel
            (goto-char (point-min))
            (cond ((or (looking-at "No \\(manual \\)*entry for")
                       (looking-at "[^\n]*: nothing appropriate$"))
-                  (setq err-mess (buffer-substring (point)
-                                                   (progn
-                                                     (end-of-line) (point)))
+                  (setq message (buffer-substring (point)
+                                                  (progn
+                                                    (end-of-line) (point)))
                         delete-buff t))
 
                  ;; "-k foo", successful exit, but no output (from man-db)
@@ -1415,7 +1415,7 @@ Man-bgproc-sentinel
                        (eq (process-status process) 'exit)
                        (= (process-exit-status process) 0)
                        (= (point-min) (point-max)))
-                  (setq err-mess (format "%s: no matches" Man-arguments)
+                  (setq message (format "%s: no matches" Man-arguments)
                         delete-buff t))
 
                  ((or (stringp process)
@@ -1423,7 +1423,7 @@ Man-bgproc-sentinel
                                 (= (process-exit-status process) 0))))
                   (or (zerop (length msg))
                       (progn
-                        (setq err-mess
+                        (setq message
                               (concat (buffer-name Man-buffer)
                                       ": process "
                                       (let ((eos (1- (length msg))))
@@ -1432,11 +1432,7 @@ Man-bgproc-sentinel
                         (goto-char (point-max))
                         (insert (format "\nprocess %s" msg))))
                   ))
-           (if delete-buff
-               (if (window-live-p (get-buffer-window Man-buffer t))
-                   (quit-restore-window
-                    (get-buffer-window Man-buffer t) 'kill)
-                 (kill-buffer Man-buffer))
+           (unless delete-buff
 
              (run-hooks 'Man-cooked-hook)
 
@@ -1447,10 +1443,8 @@ Man-bgproc-sentinel
 
              (if (not Man-page-list)
                  (let ((args Man-arguments))
-                   (if (window-live-p (get-buffer-window (current-buffer) t))
-                       (quit-restore-window
-                        (get-buffer-window (current-buffer) t) 'kill)
-                     (kill-buffer (current-buffer)))
+                    (setq delete-buff t)
+
                     ;; Entries hyphenated due to the window's width
                     ;; won't be found in the man database, so remove
                     ;; the hyphenation -- assuming Groff hyphenates
@@ -1460,22 +1454,29 @@ Man-bgproc-sentinel
                    (if (string-match "[-‐­]" args)
                        (let ((str (replace-match "" nil nil args)))
                          (Man-getpage-in-background str))
-                      (message "Can't find the %s manpage"
-                               (Man-page-from-arguments args))))
+                      (setq message (format "Can't find the %s manpage"
+                                            (Man-page-from-arguments args)))))
 
                (if Man-fontify-manpage-flag
-                   (message "%s man page formatted"
-                            (Man-page-from-arguments Man-arguments))
-                 (message "%s man page cleaned up"
-                          (Man-page-from-arguments Man-arguments)))
+                   (setq message (format "%s man page formatted"
+                                         (Man-page-from-arguments 
Man-arguments)))
+                 (setq message (format "%s man page cleaned up"
+                                       (Man-page-from-arguments 
Man-arguments))))
                (unless (and (processp process)
                             (not (eq (process-status process) 'exit)))
                  (setq mode-line-process nil))
-               (set-buffer-modified-p nil)))))
+               (set-buffer-modified-p nil))))))
 
-       (if err-mess
-           (message "%s" err-mess))
-       ))))
+      (when delete-buff
+        (if (window-live-p (get-buffer-window Man-buffer t))
+           (quit-restore-window
+            (get-buffer-window Man-buffer t) 'kill)
+         (kill-buffer Man-buffer)))
+
+      (when message
+        (if (minibufferp)
+            (minibuffer-message "%s" message)
+          (message "%s" message))))))
 
 (defun Man-page-from-arguments (args)
   ;; Skip arguments and only print the page name.