Re: A new(?) warning of erase-buffer, which was not seen before.

[martin rudalics <rudalics@gmx.at>]

 >>>> My attempted solution was to scan through buffer-undo-list, updating
 >>>> those position, every time I inserted some "hidden from undo" text.
 >>>> [This isn't typically a performance problem because _usually_
 >>>> buffer-undo-list is nil when process output is occuring.]
 >>
 >>
 >>> That's exactly what ERC does.  See erc-update-undo-list.
 >>
 >>
 >> I.e. we should probably add a "insert-without-undo" function which does
 >> just that.
 >
 >
 > Yes, please. And also an delete-without-undo.

You can't do that by simply scanning the buffer-undo-list and comparing
positions.  If I recall correctly `erc-update-undo-list' doesn't even
handle the simple case where the undo list records an insertion from A
to B, and you want to insert a text from C to D where A < C and D < B.
It would either modify both A and B or none of them.