(rmail-toggle-header): Redo previous change;

don't move point if possible.
(rmail-count-screen-lines): Add.

diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index b94f4657c6f625c9d5c5a62e7acbc4d05e8f745f..0f3063769a8d3fd6769ac3e9527db421fbcdd668 100644 (file)
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -1780,42 +1780,65 @@ Otherwise, delete all header fields whose names match `rmail-ignored-headers'."
 With argument ARG, show the message header pruned if ARG is greater than zero;
 otherwise, show it in full."
   (interactive "P")
+  (let* ((buffer-read-only nil)
+        (pruned (rmail-msg-is-pruned))
+        (prune (if arg
+                   (> (prefix-numeric-value arg) 0)
+                 (not pruned))))
+    (if (eq pruned prune)
+       t
+      (rmail-maybe-set-message-counters)
+      (let ((at-point-min (= (point) (point-min)))
+            (all-headers-visible (= (window-start) (point-min)))
+            (on-header (save-excursion
+                         (and (not (search-backward "\n\n" nil t))
+                              (progn
+                                (end-of-line)
+                                (re-search-backward "^[-A-Za-z0-9]+:" nil t))
+                              (match-string 0))))
+            (old-screen-line (rmail-count-screen-lines (window-start) (point))))
+        (save-excursion
+      (narrow-to-region (rmail-msgbeg rmail-current-message) (point-max))
+      (if pruned
+         (progn (goto-char (point-min))
+                (forward-line 1)
+                (delete-char 1)
+                (insert ?0)
+                (forward-line 1)
+                (let ((case-fold-search t))
+                  (while (looking-at "Summary-Line:\\|Mail-From:")
+                    (forward-line 1)))
+                (insert "*** EOOH ***\n")
+                (forward-char -1)
+                    (search-forward "\n*** EOOH ***\n")
+                    (narrow-to-region (point) (point-max)))
+           (rmail-reformat-message (point-min) (point-max))))
+       (cond (at-point-min
+              (goto-char (point-min)))
+             (on-header
+              (goto-char (point-min))
+              (search-forward "\n\n")
+              (or (re-search-backward (concat "^" (regexp-quote on-header)) nil t)
+                  (goto-char (point-min))))
+             (t
+              (recenter old-screen-line)
+              (if (and all-headers-visible
+                       (not (= (window-start) (point-min))))
+                  (let ((lines-offscreen (rmail-count-screen-lines
+                                          (point-min) (window-start))))
+                    (recenter (min (+ old-screen-line lines-offscreen)
+                                   ;; last line of window
+                                   (- (window-height) 2))))))))
+      (rmail-highlight-headers))))
+
+;; Lifted from repos-count-screen-lines.
+;; Return number of screen lines between START and END.
+(defun rmail-count-screen-lines (start end)
   (save-excursion
-    (let* ((buffer-read-only nil)
-          (pruned (rmail-msg-is-pruned))
-          (prune (if arg
-                     (> (prefix-numeric-value arg) 0)
-                   (not pruned))))
-      (if (eq pruned prune)
-         t
-       (rmail-maybe-set-message-counters)
-       (narrow-to-region (rmail-msgbeg rmail-current-message) (point-max))
-       (if pruned
-           (let (window-at-top)
-             (goto-char (point-min))
-             (forward-line 1)
-             (delete-char 1)
-             (insert ?0)
-             (forward-line 1)
-             (let ((case-fold-search t))
-               (while (looking-at "Summary-Line:\\|Mail-From:")
-                 (forward-line 1)))
-             (insert "*** EOOH ***\n")
-             (forward-char -1)
-             (search-forward "\n*** EOOH ***\n")
-             (forward-line -1)
-             (let ((temp (point)))
-               (when (search-forward "\n\n" nil t)
-                 (if (< (window-start) (point))
-                     (setq window-at-top t))
-                 (delete-region temp (point))))
-             (goto-char (point-min))
-             (search-forward "\n*** EOOH ***\n")
-             (if window-at-top
-                 (set-window-start (selected-window) (point) t))
-             (narrow-to-region (point) (point-max)))
-         (rmail-reformat-message (point-min) (point-max)))
-       (rmail-highlight-headers)))))
+    (save-restriction
+      (narrow-to-region start end)
+      (goto-char (point-min))
+      (vertical-motion (- (point-max) (point-min))))))
 \f
 ;;;; *** Rmail Attributes and Keywords ***