Re: How can I undo a change from a modification-hook?

[Clément Pit-Claudel]

On 2017-04-26 09:52, Stefan Monnier wrote:
>>> [ and while you're there, check that the beg/end/len is within the
>>> announces beg/end stashed earlier, and if it's not just don't do
>>> anything since it means the stash buffer-undo-list is likely
>>> unrelated.  ]
>> This part worries me.  Could you clarify when this would happen?
> 
> In rare corner cases (most of them bugs).
> 
>> Not doing anything is risky, because it puts the buffer in an inconsistent
>> state wrt the subprocess :/
> 
> In the case of PG, I'd suggest you treat such a case as
> a non-whitespace change.

But I can't, can I? The damage (the change) is already done at that point, and 
I can't revert it. Am I missing something?

Clément.