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

2 files changed, 80 insertions, 70 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index a1a1b7b1a08..8cb6d664b06 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,7 @@
+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
diff --git a/lisp/comint.el b/lisp/comint.el
index 21e318e2112..f890090c29a 100644
--- a/lisp/comint.el
+++ b/lisp/comint.el
@@ -1487,83 +1487,89 @@ 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)
-                (nchars (length string))
-                (ostart nil))
-            (widen)
-            (goto-char (process-mark process))
-            (setq ostart (point))
-            (if (<= (point) opoint)
-                (setq opoint (+ opoint nchars)))
-            ;; Insert after old_begv, but before old_zv.
-            (if (< (point) obeg)
-                (setq obeg (+ obeg nchars)))
-            (if (<= (point) oend)
-                (setq oend (+ oend nchars)))
-
-            (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.
-              (if (and comint-last-output-overlay
-                       (equal (overlay-end comint-last-output-overlay) ostart))
-                  ;; Extend comint-last-output-overlay to include the
-                  ;; most recent output
-                  (move-overlay comint-last-output-overlay
-                                (overlay-start comint-last-output-overlay)
-                                (point))
-                ;; Create a new overlay
-                (let ((over (make-overlay ostart (point))))
-                  (overlay-put over 'field 'output)
-                  (overlay-put over 'rear-nonsticky t)
-                  (overlay-put over 'inhibit-line-move-field-capture t)
-                  (overlay-put over 'evaporate t)
-                  (setq comint-last-output-overlay over))))
-
-            (when comint-highlight-prompt
-              ;; Highlight the prompt, where we define `prompt' to mean
-              ;; the most recent output that doesn't end with a newline.
-              (unless (and (bolp) (null comint-last-prompt-overlay))
-                ;; Need to create or move the prompt overlay (in the
-                ;; case where's no prompt ((bolp) == t), we still do
-                ;; this if there's already an existing overlay.
-                (let ((prompt-start (save-excursion (forward-line 0) (point))))
-                  (if comint-last-prompt-overlay
-                      ;; Just move an existing overlay
-                      (move-overlay comint-last-prompt-overlay
-                                    prompt-start (point))
-                    ;; Need to create the overlay
-                    (setq comint-last-prompt-overlay
-                          (make-overlay prompt-start (point)))
-                    (overlay-put comint-last-prompt-overlay
-                                 'rear-nonsticky t)
-                    (overlay-put comint-last-prompt-overlay
-                                 'face 'comint-highlight-prompt-face)))))
-
-            ;; Don't insert initial prompt outside the top of the window.
-            (if (= (window-start (selected-window)) (point))
-                (set-window-start (selected-window) (- (point) (length string))))
-            (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-output-start ostart)
-            (set-marker (process-mark process) (point))
-            (force-mode-line-update))
 
+        ;; 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 (process-mark process)))
+          (widen)
+          (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.
+          (if (< (point) obeg)
+              (setq obeg (+ obeg nchars)))
+          (if (<= (point) oend)
+              (setq oend (+ oend nchars)))
+
+          (insert string)
+
+          (unless comint-use-prompt-regexp-instead-of-fields
+            ;; 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
+                ;; most recent output
+                (move-overlay comint-last-output-overlay
+                              (overlay-start comint-last-output-overlay)
+                              (point))
+              ;; Create a new overlay
+              (let ((over (make-overlay ostart (point))))
+                (overlay-put over 'field 'output)
+                (overlay-put over 'rear-nonsticky t)
+                (overlay-put over 'inhibit-line-move-field-capture t)
+                (overlay-put over 'evaporate t)
+                (setq comint-last-output-overlay over))))
+
+          (when comint-highlight-prompt
+            ;; Highlight the prompt, where we define `prompt' to mean
+            ;; the most recent output that doesn't end with a newline.
+            (unless (and (bolp) (null comint-last-prompt-overlay))
+              ;; Need to create or move the prompt overlay (in the
+              ;; case where's no prompt ((bolp) == t), we still do
+              ;; this if there's already an existing overlay.
+              (let ((prompt-start (save-excursion (forward-line 0) (point))))
+                (if comint-last-prompt-overlay
+                    ;; Just move an existing overlay
+                    (move-overlay comint-last-prompt-overlay
+                                  prompt-start (point))
+                  ;; Need to create the overlay
+                  (setq comint-last-prompt-overlay
+                        (make-overlay prompt-start (point)))
+                  (overlay-put comint-last-prompt-overlay
+                               'rear-nonsticky t)
+                  (overlay-put comint-last-prompt-overlay
+                               'face 'comint-highlight-prompt-face)))))
+
+          ;; Don't insert initial prompt outside the top of the window.
+          (if (= (window-start (selected-window)) (point))
+              (set-window-start (selected-window) (- (point) (length string))))
+          (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-output-start ostart)
+          (set-marker (process-mark process) (point))
+          (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 ()