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

Switch buffers only after calling `help-buffer'.

1 files changed, 41 insertions, 37 deletions

diff --git a/lisp/help.el b/lisp/help.el
index d4b5ceacb4d..8d27ce5a046 100644
--- 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))))
 
 
 ;;; Automatic resizing of temporary buffers.