Re: bidi, auto-composition-mode

Re: bidi, auto-composition-mode

[Angelo Graziosi]

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Eduard Wiebe wrote:
> I'm playing with the new bidi-feature, thanks Eli, and receive a
> strange result.
[...]
> the display order
> indeed reversed but some characters are duplicated (s. attachment).

The same happens on Cygwin (GTK build of the trunk).

Trying to write "This is a test", it writes, initially, two T instead of 
one, so the result is

This is a testT
              ^^^
I have attached a screen shot.

> The effect of duplicated characters disappers if i switch
> auto-composition-mode on.

Confirmed also on Cygwin!

Thanks,
Angelo.

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Re: bidi, auto-composition-mode

[Eli Zaretskii]

> Date: Wed, 21 Apr 2010 01:00:38 +0200
> From: Angelo Graziosi <angelo.graziosi@alice.it>
> CC: Eli Zaretskii <eliz@gnu.org>
> 
> Eduard Wiebe wrote:
> > I'm playing with the new bidi-feature, thanks Eli, and receive a
> > strange result.
> [...]
> > the display order
> > indeed reversed but some characters are duplicated (s. attachment).
> 
> The same happens on Cygwin (GTK build of the trunk).
> 
> Trying to write "This is a test", it writes, initially, two T instead of 
> one, so the result is
> 
> This is a testT
>               ^^^

??? The OP used Hebrew letters and auto-composed characters, but you
used only ASCII, so this is a different problem.  Please tell me what
did you type to get this displayed flushed to the right and T doubled.

Re: bidi, auto-composition-mode

[Angelo Graziosi]

Il 21/04/2010 5.09, Eli Zaretskii ha scritto:
>> Date: Wed, 21 Apr 2010 01:00:38 +0200
>> From: Angelo Graziosi<angelo.graziosi@alice.it>
>> CC: Eli Zaretskii<eliz@gnu.org>
>>
>> Eduard Wiebe wrote:
>>> I'm playing with the new bidi-feature, thanks Eli, and receive a
>>> strange result.
>> [...]
>>> the display order
>>> indeed reversed but some characters are duplicated (s. attachment).
>>
>> The same happens on Cygwin (GTK build of the trunk).
>>
>> Trying to write "This is a test", it writes, initially, two T instead of
>> one, so the result is
>>
>> This is a testT
>>                ^^^
>
> ??? The OP used Hebrew letters and auto-composed characters, but you
> used only ASCII, so this is a different problem.  Please tell me what
> did you type to get this displayed flushed to the right and T doubled.

OK. In my $HOME/.emacs.d/init.el file I have added this:

;; Use C-x 8 RET RIGHT-TO-LEFT MARK to write from right to left
(setq-default bidi-display-reordering t)

Then, in Emacs, I do this

C-x C-f foo.txt
C-x 8 RET RIGHT-TO-LEFT MARK

Then I start to type "This is a test" (all starts to the right, 
obviously). When I type the firt 'T', really in Emacs, I see two 'T',

TT

Then, I type 'h',

ThT

and so on

ThiT
ThisT
This iT
This isT
...
This is a testT

with the cursor always to the left of the most left 'T' (that near the 
'h', i.e. 'Th'). If now I do

M-x auto-composition-mode

the result is:

This is a test

without the most right 'T'!

I obtain the *same* results both on Cygwin and on GNU/Linux kubuntu 9.10 
(GTK builds rev. >= 99951).

Ciao,
Angelo.

Re: bidi, auto-composition-mode

[Eli Zaretskii]

> Date: Wed, 21 Apr 2010 10:05:30 +0200
> From: Angelo Graziosi <angelo.graziosi@alice.it>
> CC: emacs-devel@gnu.org
> 
> OK. In my $HOME/.emacs.d/init.el file I have added this:
> 
> ;; Use C-x 8 RET RIGHT-TO-LEFT MARK to write from right to left
> (setq-default bidi-display-reordering t)
> 
> Then, in Emacs, I do this
> 
> C-x C-f foo.txt
> C-x 8 RET RIGHT-TO-LEFT MARK

Thanks, now everything is clear.  Emacs composes the RIGHT-TO-LEFT
MARK (and other zero-width characters) with the next character, and
compositions don't yet work with bidi reordering.  The effect is
indeed duplication of characters.  You can see another example of this
problem in HELLO, in the Arabic and Hebrew lines -- they also use RLM.

Re: bidi, auto-composition-mode [core dump]

[Angelo Graziosi]

Il 21/04/2010 18.12, Eli Zaretskii ha scritto:
>> Date: Wed, 21 Apr 2010 10:05:30 +0200
>> From: Angelo Graziosi<angelo.graziosi@alice.it>
>> CC: emacs-devel@gnu.org
>>
>> OK. In my $HOME/.emacs.d/init.el file I have added this:
>>
>> ;; Use C-x 8 RET RIGHT-TO-LEFT MARK to write from right to left
>> (setq-default bidi-display-reordering t)
>>
>> Then, in Emacs, I do this
>>
>> C-x C-f foo.txt
>> C-x 8 RET RIGHT-TO-LEFT MARK
>
> Thanks, now everything is clear.  Emacs composes the RIGHT-TO-LEFT
> MARK (and other zero-width characters) with the next character, and
> compositions don't yet work with bidi reordering.  The effect is
> indeed duplication of characters.  You can see another example of this
> problem in HELLO, in the Arabic and Hebrew lines -- they also use RLM.

Just now, I have discovered (with rev. 100032) that Emacs does not like 
any more this:

(setq-default bidi-display-reordering t)

in my initialization file: it aborts!

To reproduce: add the above to .emacs (or to .emacs.d/init.el) file; 
then 'short circuit' the desktop file, if any. For example renaming it:

mv desktop desktop.save

In this way Emacs should starts with the 'scratch' buffer.

Then

$ emacs &

aborts. If you want to use the desktop file, after Emacs is started, you 
should switch buffer up to the 'scratch', for example clicking with 
mouse-1 on buffer name in the mode line: then switching from 'Messages' 
buffer to scratch' causes Emacs to abort.

In short, Emacs does not like the above (setq...) in .emacs and the 
'scratch' buffer.

I have verified this both on GNU/Linux Kubuntu 9.10 and on Cygwin.

Ciao,
Angelo.

Re: bidi, auto-composition-mode [core dump]

[Eli Zaretskii]

> Date: Sun, 25 Apr 2010 18:13:56 +0200
> From: Angelo Graziosi <angelo.graziosi@alice.it>
> CC: emacs-devel@gnu.org
> 
> Just now, I have discovered (with rev. 100032) that Emacs does not like 
> any more this:
> 
> (setq-default bidi-display-reordering t)
> 
> in my initialization file: it aborts!

This is bug#6030.  I already have a fix for it, and will commit in a
short while.

Thanks.

Re: bidi, auto-composition-mode [core dump]

[Eli Zaretskii]

> Date: Sun, 25 Apr 2010 19:22:42 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: emacs-devel@gnu.org
> 
> > Date: Sun, 25 Apr 2010 18:13:56 +0200
> > From: Angelo Graziosi <angelo.graziosi@alice.it>
> > CC: emacs-devel@gnu.org
> > 
> > Just now, I have discovered (with rev. 100032) that Emacs does not like 
> > any more this:
> > 
> > (setq-default bidi-display-reordering t)
> > 
> > in my initialization file: it aborts!
> 
> This is bug#6030.  I already have a fix for it, and will commit in a
> short while.

Done.