(comint-send-input): Make the newline boundary overlay rear-nonsticky.

Use `insert' instead of `insert-before-markers'.
(comint-output-filter): Use `insert' instead of `insert-before-markers'.
Extend comint-last-output-overlay when necessary since we can't rely on
insert-before-markers to do it.

1 files changed, 11 insertions, 5 deletions

diff --git a/lisp/comint.el b/lisp/comint.el
index 15d6a12b335..21e318e2112 100644
--- a/lisp/comint.el
+++ b/lisp/comint.el
@@ -1396,7 +1396,7 @@ Similarly for Soar, Scheme, etc."
 
           (if comint-process-echoes
               (delete-region pmark (point))
-            (insert-before-markers ?\n))
+            (insert ?\n))
 
           (if (and (funcall comint-input-filter history)
                    (or (null comint-input-ignoredups)
@@ -1430,6 +1430,7 @@ Similarly for Soar, Scheme, etc."
               ;; Make an overlay for the terminating newline
               (let ((over (make-overlay end (1+ end))))
                 (overlay-put over 'field 'boundary)
+                (overlay-put over 'rear-nonsticky t)
                 (overlay-put over 'evaporate t))))
 
           (comint-snapshot-last-prompt)
@@ -1507,16 +1508,21 @@ This variable is permanent-local.")
                 (setq obeg (+ obeg nchars)))
             (if (<= (point) oend)
                 (setq oend (+ oend nchars)))
-            (insert-before-markers string)
+
+            (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.
-              (unless (and comint-last-output-overlay
-                           (equal (overlay-end comint-last-output-overlay)
-                                  (point)))
+              (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)