(describe-mode): Call help-setup-xref in the help buffer.

Switch buffers only after calling `help-buffer'.

diff --git a/lisp/help.el b/lisp/help.el
index d4b5ceacb4df345bdfbf1e3249c3ff25c22fd970..8d27ce5a04665e397cfce295f40d0482a2c3b2d1 100644 (file)
--- a/lisp/help.el
+++ b/lisp/help.el
@@ -501,45 +501,49 @@ For this to work correctly for a minor mode, the mode's indicator variable
 \(listed in `minor-mode-alist') must also be a function whose documentation
 describes the minor mode."
   (interactive)
-  (when buffer (set-buffer buffer))
-  (help-setup-xref (list #'describe-mode (current-buffer)) (interactive-p))
+  (help-setup-xref (list #'describe-mode (or buffer (current-buffer)))
+                  (interactive-p))
+  ;; For the sake of help-do-xref and help-xref-go-back,
+  ;; don't switch buffers before calling `help-buffer'.
   (with-output-to-temp-buffer (help-buffer)
-    (when minor-mode-alist
-      (princ "The major mode is described first.
+    (save-excursion
+      (when buffer (set-buffer buffer))
+      (when minor-mode-alist
+       (princ "The major mode is described first.
 For minor modes, see following pages.\n\n"))
-    (princ mode-name)
-    (princ " mode:\n")
-    (princ (documentation major-mode))
-    (let ((minor-modes minor-mode-alist))
-      (while minor-modes
-       (let* ((minor-mode (car (car minor-modes)))
-              (indicator (car (cdr (car minor-modes)))))
-         ;; Document a minor mode if it is listed in minor-mode-alist,
-         ;; bound locally in this buffer, non-nil, and has a function
-         ;; definition.
-         (if (and (boundp minor-mode)
-                  (symbol-value minor-mode)
-                  (fboundp minor-mode))
-             (let ((pretty-minor-mode minor-mode))
-               (if (string-match "\\(-minor\\)?-mode\\'"
-                                 (symbol-name minor-mode))
-                   (setq pretty-minor-mode
-                         (capitalize
-                          (substring (symbol-name minor-mode)
-                                     0 (match-beginning 0)))))
-               (while (and indicator (symbolp indicator)
-                           (boundp indicator)
-                           (not (eq indicator (symbol-value indicator))))
-                 (setq indicator (symbol-value indicator)))
-               (princ "\n\f\n")
-               (princ (format "%s minor mode (%s):\n"
-                              pretty-minor-mode
-                              (if indicator
-                                  (format "indicator%s" indicator)
-                                "no indicator")))
-               (princ (documentation minor-mode)))))
-       (setq minor-modes (cdr minor-modes))))
-    (print-help-return-message)))
+      (princ mode-name)
+      (princ " mode:\n")
+      (princ (documentation major-mode))
+      (let ((minor-modes minor-mode-alist))
+       (while minor-modes
+         (let* ((minor-mode (car (car minor-modes)))
+                (indicator (car (cdr (car minor-modes)))))
+           ;; Document a minor mode if it is listed in minor-mode-alist,
+           ;; bound locally in this buffer, non-nil, and has a function
+           ;; definition.
+           (if (and (boundp minor-mode)
+                    (symbol-value minor-mode)
+                    (fboundp minor-mode))
+               (let ((pretty-minor-mode minor-mode))
+                 (if (string-match "\\(-minor\\)?-mode\\'"
+                                   (symbol-name minor-mode))
+                     (setq pretty-minor-mode
+                           (capitalize
+                            (substring (symbol-name minor-mode)
+                                       0 (match-beginning 0)))))
+                 (while (and indicator (symbolp indicator)
+                             (boundp indicator)
+                             (not (eq indicator (symbol-value indicator))))
+                   (setq indicator (symbol-value indicator)))
+                 (princ "\n\f\n")
+                 (princ (format "%s minor mode (%s):\n"
+                                pretty-minor-mode
+                                (if indicator
+                                    (format "indicator%s" indicator)
+                                  "no indicator")))
+                 (princ (documentation minor-mode)))))
+         (setq minor-modes (cdr minor-modes))))
+      (print-help-return-message))))
 
 \f
 ;;; Automatic resizing of temporary buffers.