[NTG-context] bug in latest beta?

[Otared Kavian]

Hi Pablo,

Indeed the document I was talking about has been typeset with various versions of mkiv, but now I observe that sometimes the pagebreaks are made in a very strange way. Since I can’t make a minimal example, I put on the following link an excerpt of the PDF document where the bad pagebreaks can be seen: 

	https://dl.dropboxusercontent.com/u/4316076/bad-pagebreak.pdf

(Please see pages 19 and 32). It seems that this happens, sometimes, but as far as I can say from my experiments the bad pagebreak happens always before a « proclaim » which is defined as follows:

\defineenumeration[proclaim]
	[text=,
	before={\blank\startbackground[frame=off,leftframe=on,
				rulethickness=2pt,framecolor=darkred,
				background=color,
				backgroundcolor=screen]},
	after={\stopbackground\blank},
	style=slanted,
	title=yes,
	titleleft=,
	titleright={.},
	alternative=hanging,
	width=fit,
	right={~},
	way=bysection,
	prefix=yes,
	prefixsegments={chapter:section}]

Actually I found a workaround for this by changing the above definition into:

\defineenumeration[proclaim]
	[text=,
	before={\blank\startmarginrule[rulethickness=1pt,rulecolor=darkred]},
	after={\stopmarginrule},
	style=slanted,
	title=yes,
	titleleft=,
	titleright={.},
	alternative=hanging,
	width=fit,
	right={~},
	way=bysection,
	prefix=yes,
	prefixsegments={chapter:section}]

However it would be better to understand why the first definition does not work properly, in a rather random way.

Best regards: OK


> On 01 Jun 2015, at 00:16, Hans Hagen <pragma at wxs.nl> wrote:
> 
> On 5/31/2015 1:56 PM, Pablo Rodriguez wrote:
>> On 05/28/2015 07:10 PM, Hans Hagen wrote:
>>> On 5/27/2015 10:38 PM, Pablo Rodriguez wrote:
>>>> [...]
>>>> Compiling it with beta from 2015.03.25 22:13, page break is fine.
>>>> 
>>>> But with latest beta from 2015.05.24 12:42 (or even with beta from
>>>> 2015.05.15 11:42 includes a wrong page break. The setups for widow and
>>>> orphan lines move the two last lines to the next page.
>>>> 
>>>> Could anyone confirm this bug?
>>> 
>>> i wonder if it's a bug or just tex's decision ... you can use
>>> 
>>> \showmakeup[penalty]
>>> 
>>> and see what penalties get injected
>>> 
>>> are the linebreaks identical, i.e. same hyphenation?
>> 
>> Many thanks for your reply, Hans.
>> 
>> Hyphenation is the same in both documents.
>> 
>>> btw, brokenpenalty 1 gives a different result
>> 
>> Page break is wrong when any of the three values (brokenpenalty,
>> widowpenalty or clubpenalty) is 0 or above 9999.
>> 
>> I replacing \subsection with \section gives the right page break:
>> 
>>     \showframe\showgrid
>>     \setuplayout[setups=*lessstrict]
>>     \startsetups[*lessstrict]
>>         \setup[reset]
>>         \widowpenalty=10000
>>         \clubpenalty=10000
>>         \brokenpenalty=0
>>     \stopsetups
>>     \setupbodyfont[pagella, 12.6pt]
>>     \starttext
>>     \chapter{Quotes}
>>     \section{Zapf}
>>     \dorecurse{4}{\input zapf\par}
>>     \section{Knuth}
>>     \input knuth
>>     \stoptext
>> 
>> Why does \subsection cause a different page break than \section?
> 
> because there are penalties related to (sub)sections in a way that keeps them together but at the same time still permits breaks in case of too many successive ones .. and penalties determine the way the page is broken
> 
> Hans
> 
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