(rmail-show-message): Use overlays, not text properties.

(rmail-overlay-list): New variable.
(rmail-mode): Make it local.

diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index 16b11d00caa322f3334869d4f6f1210276e5df28..275367808fe7bab1d8c709f1282b252d77fa85ab 100644 (file)
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -125,6 +125,8 @@ Called with region narrowed to the message, including headers.")
 (defvar rmail-message-vector nil)
 (defvar rmail-deleted-vector nil)
 
+(defvar rmail-overlay-list nil)
+
 ;; These are used by autoloaded rmail-summary.
 
 (defvar rmail-summary-buffer nil)
@@ -575,6 +577,8 @@ Instead, these commands are available:
   (make-local-variable 'rmail-total-messages)
   (make-local-variable 'require-final-newline)
   (setq require-final-newline nil)
+  (make-local-variable 'rmail-overlay-list)
+  (setq rmail-overlay-list nil)
   (make-local-variable 'version-control)
   (setq version-control 'never)
   (make-local-variable 'file-precious-flag)
@@ -1403,18 +1407,32 @@ If summary buffer is currently displayed, update current message there also."
                  ;; Highlight with boldface if that is available.
                  ;; Otherwise use the `highlight' face.
                  (face (if (face-differs-from-default-p 'bold)
-                           'bold 'highlight)))
+                           'bold 'highlight))
+                 ;; List of overlays to reuse.
+                 (overlays rmail-overlay-list))
              (goto-char (point-min))
              (while (re-search-forward rmail-highlighted-headers nil t)
                (skip-syntax-forward " ")
-               (let ((beg (point)))
+               (let ((beg (point))
+                     overlay)
                  (while (progn (forward-line 1)
                                (looking-at "[ \t]")))
                  ;; Back up over newline, then trailing spaces or tabs
                  (forward-char -1)
                  (while (member (preceding-char) '(?  ?\t))
                    (forward-char -1))
-                 (put-text-property beg (point) 'face face))))))
+                 (if overlays
+                     ;; Reuse an overlay we already have.
+                     (progn
+                       (setq overlay (car overlays)
+                             overlays (cdr overlays))
+                       (move-overlay overlay beg (point)))
+                   ;; Make a new overlay and add it to
+                   ;; rmail-overlay-list.
+                   (setq overlay (make-overlay beg beg))
+                   (overlay-put overlay 'face face)
+                   (setq rmail-overlay-list
+                         (cons overlay rmail-overlay-list))))))))
        (run-hooks 'rmail-show-message-hook)
        ;; If there is a summary buffer, try to move to this message
        ;; in that buffer.  But don't complain if this message