[luatex] interline penalty for 2 line paragraphs

[Hans Hagen]

On 9/5/2016 4:01 PM, David Carlisle wrote:
> Hi, another oddity in the dev build,
>
> given
>
>
> \tracingonline1
> \tracingoutput1
> \showboxdepth10
> \showboxbreadth10
>
> \message{\the\interlinepenalty, \the\clubpenalty, \the\widowpenalty}
>
> x\hfill\break y
>
> \bye
>
>
> pdftex and luatex 0.95 give an interline penalty of 300 (= club + widow)
>
>
> ...\glue(\rightskip) 0.0
> ..\penalty 300
> ..\glue(\baselineskip) 7.69446
>
>
> but 0.98.4 gives a penalty of 156 ??
>
>
> ...\glue(\rightskip) 0.0
> ..\penalty 156
> ..\glue(\baselineskip) 7.69446

ah, indeed, the 6 is the internal register number of widow_penalty:

linebreak.w: line 186

                           (d ? display_widow_penalty_par : 
widow_penalty_par),

(so add _par) ... a side effect of normalizing all kind of register 
access so that one got lost

Hans

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