bug#810: 23.0.60; atomic-change-group narrowing problem

[Stefan Monnier <monnier@iro.umontreal.ca>]

>>>>> When using atomic-change-group I got the message
>>>>> undo-more: Changes to be undone are outside visible portion of buffer
>>>>> The changes are also not undone. This seems wrong to me.
>>> 
>>>> The attached patch now also tries to restore any narrowing in force
>>>> before the atomic change.
>>> 
>>> I'm not sure we should do that.  Currently, narrowing operations are not
>>> saved to the undo-log, so making atomic-change-group save&restore the
>>> narrowing makes it behave differently from the undo.
>> 
>> I know what you mean but the present case is different.  When someone
>> uses narrowing within the atomic change group and we really want to undo
>> the changes (we still can decide that we won't fix the bug ;-)) we have
>> to widen the buffer.  If the buffer was narrowed _before_ entering the
>> atomic change group, it would be incorrect not to restore that.  Or am I
>> missing something?

The widening needs to be temporary around the call to undo, but that
doesn't seem to imply that atomic-change-group will preserve narrowing.


        Stefan