* progmodes/compile.el (compilation-filter): If inserting at end

of accessible part of buffer, keep end of output visible.

2 files changed, 14 insertions, 2 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index b1241123942..cfc11bd2e40 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,8 @@
 2009-05-18  Richard M Stallman  <rms@gnu.org>
 
+        * progmodes/compile.el (compilation-filter): If inserting at end
+        of accessible part of buffer, keep end of output visible.
+
         * mail/rmail.el (rmail-expunge-confirmed): Return nil if nothing to do.
         Don't call rmail-modify-format here.
         (rmail-expunge): Call it here after expunge is confirmed.
diff --git a/lisp/progmodes/compile.el b/lisp/progmodes/compile.el
index 2b3b954a412..283a37acd8c 100644
--- a/lisp/progmodes/compile.el
+++ b/lisp/progmodes/compile.el
@@ -1739,9 +1739,15 @@ and runs `compilation-filter-hook'."
     (with-current-buffer (process-buffer proc)
       (let ((inhibit-read-only t)
             ;; `save-excursion' doesn't use the right insertion-type for us.
-            (pos (copy-marker (point) t)))
+            (pos (copy-marker (point) t))
+            (min (point-min-marker))
+            (max (point-max-marker)))
         (unwind-protect
             (progn
+              ;; If we are inserting at the end of the accessible part
+              ;; of the buffer, keep the inserted text visible.
+              (set-marker-insertion-type max t)
+              (widen)
               (goto-char (process-mark proc))
               ;; We used to use `insert-before-markers', so that windows with
               ;; point at `process-mark' scroll along with the output, but we
@@ -1751,7 +1757,10 @@ and runs `compilation-filter-hook'."
                 (comint-carriage-motion (process-mark proc) (point)))
               (set-marker (process-mark proc) (point))
               (run-hooks 'compilation-filter-hook))
-          (goto-char pos))))))
+          (goto-char pos)
+          (narrow-to-region min max)
+          (set-marker min nil)
+          (set-marker max nil))))))
 
 ;;; test if a buffer is a compilation buffer, assuming we're in the buffer
 (defsubst compilation-buffer-internal-p ()