bug#16247: syntax-ppss returns incorrect state

[Stefan Monnier]

> (
> (eval-when-compile
> |  (let ((load-path
>         (if (and (boundp 'byte-compile-dest-file)
[...]
> Why did the same buffer position change from depth 2 to depth 1, even
> though the buffer didn't change between the get-syntax calls?

That's because of syntax-begin-function, which in Lisp buffers assumes
than an open-paren in column 0 is necessarily outside of anything
(parens, comments, strings, ...).  And then syntax-ppss sometimes uses
this assumption and sometimes not, depending on the distance of the
previous call to syntax-ppss and the nearest beginning of defun (aka
open-paren in column 0).

I just installed a change to leave syntax-begin-function nil in
Lisp buffers.  The performance impact should be negligible.


        Stefan