* lisp/comint.el (comint-get-old-input-default): Fix use-prompt-regexp case.

Fixes: debbugs:9865

lisp/ChangeLog

+2011-10-25  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+	* comint.el (comint-get-old-input-default): Fix use-prompt-regexp case
+	(bug#9865).
+
 2011-10-24  Glenn Morris  <rgm@gnu.org>
 
 	* emacs-lisp/easy-mmode.el (define-minor-mode): Doc fix.  (Bug#9819)

lisp/comint.el

@@ -2151,8 +2151,10 @@ current line, if point is on an output field.
 If `comint-use-prompt-regexp' is non-nil, then return
 the current line with any initial string matching the regexp
 `comint-prompt-regexp' removed."
-  (let ((bof (field-beginning)))
-    (if (null (get-char-property bof 'field)) ;Not `output'.
+  (let (bof)
+    (if (and comint-use-prompt-regexp
+             ;; Make sure we're in an input rather than output field.
+             (null (get-char-property (setq bof (field-beginning)) 'field)))
 	(field-string-no-properties bof)
       (comint-bol)
       (buffer-substring-no-properties (point) (line-end-position)))))