From 225a48126f3ffe9cf91544ada6e157985deec77d Mon Sep 17 00:00:00 2001 From: David Aspinall Date: Mon, 12 Oct 1998 15:29:53 +0000 Subject: Added sensible error message for attempting undo on empty locked region. --- generic/proof.el | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'generic/proof.el') diff --git a/generic/proof.el b/generic/proof.el index d2aaff13..f56f577e 100644 --- a/generic/proof.el +++ b/generic/proof.el @@ -2169,8 +2169,12 @@ deletes the region corresponding to the proof sequence." Unless optional NO-DELETE is set, the text is also deleted from the proof script." (interactive "p") - (goto-char (span-start (span-at-before (proof-locked-end) 'type))) - (proof-retract-until-point (not no-delete))) + (let ((lastspan (span-at-before (proof-locked-end) 'type))) + (if lastspan + (progn + (goto-char (span-start lastspan)) + (proof-retract-until-point (not no-delete))) + (error "Nothing to undo!")))) (defun proof-interrupt-process () (interactive) -- cgit v1.2.3