Re: master a7c65fc666: Allow nil value for filter-buffer-substring-function

[Stefan Monnier]

> Ick. If `buffer-substring--filter' is the default function to call, it
> should not have the '--' internal function marker.

Why?  You're *not* supposed to call `buffer-substring--filter'.
Instead you're supposed to call the value contained in
`filter-buffer-substring-function`, whichever it is.  (and if you're
modifying this variable, then you're supposed to modify it with
`add-function` and your function will then receive the "previous"
function to call).


        Stefan