Re: Strange undo problem

[Johan Bockgård]

"Lennart Borgman (gmail)" <address@hidden> writes:

> And in elisp Info:

That is, (info "(elisp)Special Properties")

>   `modification-hooks'
>      If a character has the property `modification-hooks', then its
>      value should be a list of functions; modifying that character
>      calls all of those functions.  Each function receives two
>      arguments: the beginning and end of the part of the buffer being
>      modified.  Note that if a particular modification hook function

Wrong section. Try (info "(elisp)Overlay Properties")

    `modification-hooks'
         This property's value is a list of functions to be called if
         any character within the overlay is changed or if text is
         inserted strictly within the overlay.

         The hook functions are called both before and after each
         change.  If the functions save the information they receive,
         and compare notes between calls, they can determine exactly
         what change has been made in the buffer text.

         When called before a change, each function receives four
         arguments: the overlay, `nil', and the beginning and end of
         the text range to be modified.

         When called after a change, each function receives five
         arguments: the overlay, `t', the beginning and end of the
         text range just modified, and the length of the pre-change
         text replaced by that range.  (For an insertion, the
         pre-change length is zero; for a deletion, that length is the
         number of characters deleted, and the post-change beginning
         and end are equal.)

         If these functions modify the buffer, they should bind
         `inhibit-modification-hooks' to `t' around doing so, to avoid
         confusing the internal mechanism that calls these hooks.

-- 
Johan Bockgård