[luatex] LuaTeX v1: Two questions from testing

[Joseph Wright]

On 13/10/2016 08:01, Joseph Wright wrote:
> On 13/10/2016 07:33, Joseph Wright wrote:
>> Hello,
>>
>> Testing LuaTeX v1, there are relatively few changes from v0.95. However,
>> I've found one logging (?) change and one hyphenation change I didn't
>> expect. With example
>>
>>     \hsize 15em
>>     This is a supercalifragilisticexpialidocious%
>>      \hbox to 1em{}
>>      sentence.
>>     \tracingall
>>     \belowdisplayskip=0pt %
>>     $$
>>     y = mx + c
>>     $$
>>      \bye
>>
>> The results are different from pdfTeX in two ways. The empty \hbox does
>> not prevent hyphenation, which it has to-date (so this is not a result
>> of other hyphenation changes). The log also lacks the zero skip after
>> the display.
>>
>> It's not clear to me if either of these changes is deliberate: what's
>> the situation?
>>
>> Josph
> 
> Also, I assume that the fact the following doesn't show a \discretionary
> is deliberate:
> 
>     \tracingall
>     119-139
>      \bye
> 
> Joseph

BTW, my main concern with these is to know if it's deliberate: I'm well
aware that the log for LuaTeX is different from that for pdfTeX :)

Joseph