lyskom-trim-buffer seems to work now.

src/ChangeLog

+2000-08-31  Ulrik Haugen  <qha@lysator.liu.se>
+
+	* lyskom-rest.el (lyskom-trim-buffer): saves point and mark and
+	resets point, mark and lyskom-last-viewed after taking into
+	consideration lyskom-trim-buffer-delete-to.
+
 Thu Aug 31 14:38:34 2000  David Byers  <davby@sen2.ida.liu.se>
 
 	* Release av 0.46-BETA-Q

src/lyskom-rest.el

@@ -774,19 +774,28 @@ found in lyskom-membership, a blocking call to the server is made."
 (defvar lyskom-trim-buffer-delete-to)
 
 (defun lyskom-trim-buffer ()
-  "Trim the size of a lyskom buffer to lyskom-max-buffer-size"
+  "Trim the size of a lyskom buffer to lyskom-max-buffer-size
+returns t if it trimmed the buffer, nil otherwise."
   (when (and kom-max-buffer-size
 	     (> (- (buffer-size) kom-trim-buffer-minimum) kom-max-buffer-size))
     (lyskom-save-excursion
       (let ((lyskom-trim-buffer-delete-to (- (buffer-size)
 					     kom-max-buffer-size))
+	    (old-point (point))
+	    (old-mark (mark))
 	    (inhibit-read-only t))
 	(goto-char (point-min))
 	(while (< (point) lyskom-trim-buffer-delete-to)
 	  (forward-line 1))
 	(setq lyskom-trim-buffer-delete-to (point))
 	(run-hooks 'lyskom-trim-buffer-hook)
-	(delete-region (point-min) lyskom-trim-buffer-delete-to)))))
+	(delete-region (point-min) lyskom-trim-buffer-delete-to)
+	
+	(setq lyskom-last-viewed
+	      (- (+ lyskom-last-viewed 1) lyskom-trim-buffer-delete-to))
+	(set-mark (- (+ old-mark 1) lyskom-trim-buffer-delete-to))
+	(goto-char (- (+ old-point 1) lyskom-trim-buffer-delete-to))))
+      t))
 
 (defun lyskom-garb-lyskom-buffer-to-file ()
   "Appends the deleted initial portions of the buffer to a file.