[NTG-context] lua code prevents compilation

[Hans Hagen]

On 4/2/2015 1:21 AM, Pablo Rodriguez wrote:
> On 03/30/2015 10:33 PM, Hans Hagen wrote:
>> On 3/30/2015 5:19 PM, Pablo Rodriguez wrote:
>>> [...]
>>> For some reason unknown to me, the only way to compile the sample is to
>>> remove the luacode snippet.
>>>
>>> I need the lua code to have underscore hyphenation in type commands. And
>>> I need two extra \definehyphenationfeatures and \sethyphenationfeatures
>>> to invoke it.
>>>
>>> Have I hit a bug or what am I missing?
>>
>> I don't know as i see nothing at all with that code .. this is more fun:
>
> Many thanks for your reply, Hans,
>
> The following code shows the problem:
>
> \startluacode
>
>      function document.addfunnyhyphen(tfmdata)
>          local underscore = utf.byte("_")
>          local char       = tfmdata.characters[underscore]
>          tfmdata.characters[0xFE000]   = {
>              width    = 0,
>              height   = 0,
>              depth    = 0,
>              commands = {
>                  { "right", -char.width },
>                  { "down", char.depth },
>                  { "slot", 1, underscore },
>              }
>          }
>      end
>
>
> utilities.sequencers.appendaction("aftercopyingcharacters","after","document.addfunnyhyphen")
>
> \stopluacode
> %~ \definefontfamily[ornamenta][rm][TypographyTribute]
> \definehyphenationfeatures[underscore][righthyphenchar="FE000]
> \setuphyphenation[method=traditional]
> \sethyphenationfeatures[strict]
> \setupbodyfont[ornamenta]
> \starttext
> \hsize\zeropoint
> {\sethyphenationfeatures[underscore]\tt pandoc}
> A
> \stoptext
>
> If you uncomment the line with the font definition, font loading crashes
> compilation. It only crashes with this font
> (http://www.dafont.com/typographytribute.font) or FontAwesome
> (http://www.fontawesome.io).
>
> Both lack the underscore glyph. This causes the crash, since it works
> fine if I replace the glyph with an existing glyph in the font.
>
> Error message:
>
> code.tex: ! LuaTeX fatal error error in error handling
> \font_helpers_low_level_define ...\scaledfontmode
>                                                    \relax \ifcase
> \scaledfont...
> \font_helpers_trigger_define ..._identifier_class
>                                                    \csname
> \v_font_identifier...
> \applyfontclassstrategies ...\fontface \endcsname
>                                                    \else \expandafter
> \font_h...
> \font_helpers_synchronize_font ...classstrategies
>                                                    \fi \setfalse
> \c_font_auto...
> \rm ->\ifmmode \mathrm \else \normalrm
>                                         \fi
> \font_basics_switch_style ...ntstyle #1\endcsname
>                                                    \edef \fontstyle
> {#1}\ifmm...
> ...
>
> Would it be possible that ConTeXt silently ignores that the font doesn’t
> contain the glyph?

the message is fuzzy (and i have to check a lua stack issue maybe but 
not now) ... if char is nil then char.depth is an error

> I think this might be a bug.

 >      function document.addfunnyhyphen(tfmdata)
 >          local underscore = utf.byte("_")
 >          local char       = tfmdata.characters[underscore]

            if not char then return end

 >          tfmdata.characters[0xFE000]   = {
 >              width    = 0,
 >              height   = 0,
 >              depth    = 0,
 >              commands = {
 >                  { "right", -char.width },
 >                  { "down", char.depth },
 >                  { "slot", 1, underscore },
 >              }
 >          }
 >      end


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                                           Hans Hagen | PRAGMA ADE
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