[luatex] Why does LuaTeX show the middle dot instead of ano teleia?

[Hans Hagen]

On 8/29/2023 8:59 PM, Heiko Oberdiek via luatex wrote:
> Hello,
> 
> On 2023-08-29 20:29, Joseph Wright wrote:
>> On 29/08/2023 19:27, Heiko Oberdiek via luatex wrote:
>>>
>>> using LuaTeX to review the glyphs of a font, I discovered an oddity 
>>> about U+0387 ANO TELEIA. LuaTeX shows U+00B7 MIDDLE DOT instead.
> 
>>>          \symbol{"00B7}% MIDDLE DOT
>>>          \symbol{"0387}% ANO TELEIA
> 
>>  From UnicodeData.txt:
>>
>>      0387;GREEK ANO TELEIA;Po;0;ON;00B7;;;;N;;;;;
>>
>> so it looks like it's a simple normalisation.
> 
> Start of the UnicodeData.txt format description 
> (https://www.unicode.org/reports/tr44/#UnicodeData.txt):
>    [0] Code value
>    [1] Character name
>    [2] General category
>    [3] Canonical combining classes
>    [4] Bidirectional category
>    [5] Character decomposition
>    ...
> 
> In the LuaTeX manual, I found:
> 
> | Normalization of the Unicode input is on purpose not built-in and
> | can be handled by a macro package during callback processing.
> | We have made some practical choices and the user has to
> | live with those.
> 
> The TeX input above, however, is plain ASCII. Therefore, any 
> normalization of the file contents should not matter.
> 
> Of course, I do not want to have any decomposition that replaces
> the glyph with a different character. That would make reviewing
> the original glyph impossible.
Indeed it's not a luatex issue. Rendering in context gives two different 
glyphs with the mentioned unicodes.

Hans

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