Re: gab-buffer issue

[Mario Domenech Goulart]

On Fri, 27 Jun 2014 10:06:48 -0400 Mark H Weaver <address@hidden> wrote:

> Mario Domenech Goulart <address@hidden> writes:
>> I'm using the CHICKEN port [1] of Guile's gap-buffer implementation and
>> noticed a strange behavior in a simple test case.  I can reproduce that
>> behavior on Guile 2.0.5 and 2.0.9, but not on Guile 2.0.11.
>
> In Guile versions 2.0.0 - 2.0.9, there was a bug in 'string-copy!' such
> that it did not work properly when the source and destination ranges
> overlapped.  The characters were always copied starting from the lowest
> index, so it would fail when moving a block of characters to higher
> indices.  'string-copy!' is used by 'substring-move!', which in turn is
> used by 'gb-goto-char'.
>
> The bug was introduced in f846bd1a8f0e0d366fb8bb6944598641bc3dd246 when
> the SRFI-13 functions were updated for Unicode, and fixed in
> 793e8a9317d24298c82389bdf86b8ca17b4ee2f0.

Many thanks for the detailed and straight-to-the-point info, Mark.  It
looks like CHICKEN's string-copy! is buggy.  I've locally applied a fix
to it and can confirm it fixes the gap-buffer issue.

Best wishes.
Mario
-- 
http://parenteses.org/mario