diff options
| author |  David Aspinall <da@inf.ed.ac.uk> | 1998-10-12 15:29:53 +0000 |
|---|---|---|
| committer | David Aspinall <da@inf.ed.ac.uk> | 1998-10-12 15:29:53 +0000 |
| commit | 225a48126f3ffe9cf91544ada6e157985deec77d (patch) | |
| tree | 6f796dadc0f41c8054614f558eec7eedead861e1 /generic/proof.el | |
| parent | 83bdadc87ab58aceb9cb66171b88a263243621c5 (diff) | |
Added sensible error message for attempting undo on empty locked region.
Diffstat (limited to 'generic/proof.el')
| -rw-r--r-- | generic/proof.el | 8 |
1 files changed, 6 insertions, 2 deletions
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) |