[BRLTTY] Brltty has broken Finnish braille table

[Samuel Thibault]

Hello,

As reported in Debian:

From: Mika Hanhijärvi <miksuh at gmail.com>
> I did get a new braille display awhile ago. I have been testing it and I have
> noticed that braille table for the Finnish  language is broken. Reading text
> works but It is impossible to write text in Finnish using the integrated
> braille keyboard in the braille display. Writing text in Finnish language is
> not possible because writing scandinavian letters (which are wery commonly used
> in Finnish language) does not work. The following scandinavian letters are used
> in Finnish language. Small letters: ä, ö, å. Capital letters: Ä, Ö, Å.
> 
> It seems that the braille table for the Finnish language has many lines which
> define some weird control characters. Those lines conflict with lines defining
> scandinavian letters . If I remove those conflicting control character lines
> then both reading and writing text in Finnish works correctly.
> 
> I am a blind user from Finland so it is wery important for me that writing text
> in Finnish works. My native language is Finnish so I am really using braille in
> Finnish.
> 
> The braille table for the Finnish language is in the file:
> /etc/brltty/Text/fi.ttb
> 
> First of all these lines define scandinavian letters used in the Finnish
> language. These lines are correct and SHOULD NOT be changed:
> 
> char \xC4       (  345 7 )  # C4 ⡜ Ä [LATIN CAPITAL LETTER A WITH DIAERESIS]
> char \xC5       (1    67 )  # C5 ⡡ Å [LATIN CAPITAL LETTER A WITH RING ABOVE]
> char \xD6       ( 2 4 67 )  # D6 ⡪ Ö [LATIN CAPITAL LETTER O WITH DIAERESIS]
> char \xE4       (  345   )  # E4 ⠜ ä [LATIN SMALL LETTER A WITH DIAERESIS]
> char \xE5       (1    6  )  # E5 ⠡ å [LATIN SMALL LETTER A WITH RING ABOVE]
> char \xF6       ( 2 4 6  )  # F6 ⠪ ö [LATIN SMALL LETTER O WITH DIAERESIS]
> 
> 
> The problem described in this bug report is caused by the following lines.
> 
> This line is defined incorrectly and conflicts with the small letter "ä" ("ä"
> in Finnish braille is dots: 3, 4, 5) :
> 
> char \x84       (  345   )  # 84 ⠜   [<control-0084>]
> 
> 
> - This line conflicts with the small letter "Å" ("å" in Finnish braille is
> dots: 1, 6) :
> 
> char \x86       (1    6  )  # 86 ⠡   [START OF SELECTED AREA]
> 
> 
> - This line conflicts with the capital letter "Ä" ("Ä" in Finnish braille is
> dots: 3, 4, 5, 7) :
> 
> char \x8E       (  345 7 )  # 8E ⡜   [SINGLE SHIFT TWO]
> 
> 
> - This line conflicts with the capital letter "Å" ("Å" in Finnish braille is
> dots: 1,6,7) :
> 
> char \x8F       (1    67 )  # 8F ⡡   [SINGLE SHIFT THREE]
> 
> 
> - This line conflicts with the small letter "ö" ("ö" in Finnish braille is
> dots: 2, 4, 6) :
> 
> char \x94       ( 2 4 6  )  # 94 ⠪   [CANCEL CHARACTER]
> 
> 
> - This line conflicts with the capital letter "Ö" ("Ö" in Finnish braille is
> dots: 2, 4, 6, 7) :
> 
> char \x99       ( 2 4 67 )  # 99 ⡪   [<control-0099>]
> 
> 
> I really do not know for what and how those control characters are used, all I
> know is that if those control character lines are not commented out then
> writing text in the Finnish language is not possible. Those control character
> lines should be commented out, removed or changed so that those do not conflict
> with any other line.
> 
> I have compared the Finnish braille table with Swedish braille table because
> Swedish is the second official language in finland. It seems that the Swedish
> braille table does not define those control characters.
> 
> The braille table for the Swedish language is in the file:
> /etc/brltty/Text/sv-1996.ttb
> 
> How to reproduce this bug:
> 
> 1) select the Finnish language in the file:
> /etc/brltty.conf
> 
> Uncomment this line:
> 
> text-table      fi      # Finnish
> 
> 2) Restart brltty
> 3) connect Braille display which has integrated Braille keyboard
> 4) start e.g text editor
> 5) Try to write these scandinavian letters using the integrated Braille
> keyboard in the Braille display:
> 
> - small letter ä )braille dots: 3, 4, 5)
> - small letter ö (braille dots: 2, 4, 6)
> - small letter å (braille dots: 1, 6)
> - capital letter Ä (braille dots: 3, 4, 5, 7)
> - capital letter Ö (braille dots: 2, 4, 6, 7)
> - capital letter Å (braille dots: 1, 6, 7)