Re: Possible severe disoptimality in CCL

[Kenichi Handa <handa@m17n.org>]

In article <E1GhBZM-0007FW-Mw@fencepost.gnu.org>, Richard Stallman <rms@gnu.org> writes:

> Can you please DTRT, then ack?
[...]
> ------- Start of forwarded message -------
> Date: Sun, 05 Nov 2006 23:04:07 -0800
> From: Bob Halley <halley@play-bow.org>
[...]
> I then went looking for a reason for ccl.produced to be so wrong.  The 
> CCL program in question has a "buffer magnification" of zero, which 
> means "produce no bytes".  In this case the current destination pointer, 
> dst, is set to NULL.  A NULL dst causes the calculation of ccl->produced 
> just after the ccl_finish tag in ccl_driver() to be wrong, because the 
> code does

> ccl->produced = dst - destination

> I changed this code (patch attached) so that it set ccl->produced to 
> zero if dst was NULL.  With this change, both the type error and the 
> segfault no longer happen.  (The type error is fixed because we're no 
> longer reading random memory and treating it as encoded characters.)

You are right.  I was going to change Fccl_execute_on_string
to call ccl_driver with DESTINATION = NULL, but it seems
that your fix is better.  I've just installed it.

By the way, this bug doesn't exist in HEAD because it was
introduced in emacs-unicode-2 when I changed the interface
of ccl_driver ().

---
Kenichi Handa
handa@m17n.org