(comint-output-filter): Doc fixes & misc code cleanup.

lisp/ChangeLog

+2000-08-10  Miles Bader  <miles@gnu.org>
+
+	* comint.el (comint-output-filter): Doc fixes & misc code cleanup.
+
 2000-08-10  Eli Zaretskii  <eliz@is.elta.co.il>
 
 	* info.el (Info-file-list-for-emacs): More elements for the

lisp/comint.el

@@ -1487,20 +1487,25 @@ This variable is permanent-local.")
     ;; First check for killed buffer or no input.
     (when (and string oprocbuf (buffer-name oprocbuf))
       (with-current-buffer oprocbuf
+	;; Run preoutput filters
 	(let ((functions comint-preoutput-filter-functions))
 	  (while (and functions string)
 	    (setq string (funcall (car functions) string))
 	    (setq functions (cdr functions))))
-	(let (opoint obeg oend)
-	  (setq opoint (point))
-	  (setq obeg (point-min))
-	  (setq oend (point-max))
-	  (let ((buffer-read-only nil)
+
+	;; Do insertion.  We don't use save-restriction because it has a
+	;; bug, so we fake it by saving any current restriction, and
+	;; then later restoring it.
+	(let ((opoint (point))
+	      (obeg (point-min))
+	      (oend (point-max))
+	      (buffer-read-only nil)
 	      (nchars (length string))
-		(ostart nil))
+	      (ostart (process-mark process)))
 	  (widen)
-	    (goto-char (process-mark process))
-	    (setq ostart (point))
+	  (goto-char ostart)
+
+	  ;; Adjust buffer positions to account for about-to-be-inserted text
 	  (if (<= (point) opoint)
 	      (setq opoint (+ opoint nchars)))
 	  ;; Insert after old_begv, but before old_zv.
@@ -1512,10 +1517,8 @@ This variable is permanent-local.")
 	  (insert string)
 
 	  (unless comint-use-prompt-regexp-instead-of-fields
-	      ;; We check to see if the last overlay used for output has
-	      ;; already been extended to include STRING (because it was
-	      ;; inserted with insert-before-markers?), and only make
-	      ;; a new overlay if it hasn't.
+	    ;; We check to see if the last overlay used for output is
+	    ;; adjacent to the new input, and if so, just extend it.
 	    (if (and comint-last-output-overlay
 		     (equal (overlay-end comint-last-output-overlay) ostart))
 		;; Extend comint-last-output-overlay to include the
@@ -1557,13 +1560,16 @@ This variable is permanent-local.")
 	  (if (and comint-last-input-end
 		   (marker-buffer comint-last-input-end)
 		   (= (point) comint-last-input-end))
-		(set-marker comint-last-input-end (- comint-last-input-end nchars)))
+	      (set-marker comint-last-input-end
+			  (- comint-last-input-end nchars)))
 	  (set-marker comint-last-output-start ostart)
 	  (set-marker (process-mark process) (point))
-	    (force-mode-line-update))
+	  (force-mode-line-update)
 
+	  ;; Restore our saved restriction, and the point
 	  (narrow-to-region obeg oend)
 	  (goto-char opoint)
+
 	  (run-hook-with-args 'comint-output-filter-functions string))))))
 
 (defun comint-preinput-scroll-to-bottom ()