# [Dev-luatex] Possible issue with input from external libraries (page break problem?)

Hans Hagen pragma at wxs.nl
Wed Apr 14 20:22:20 CEST 2010

On 14-4-2010 9:45, Taco Hoekwater wrote:
> Hi Graham,
>
> Taco Hoekwater wrote:
>>
>> I don't think this is supposed to happen, but please send me the pdf
>> for a closer look and, if possible, a source to go with it that uses a
>> lua library that is available to me. I am on linux, but lxp should
>> work for me as well. I can even try to run the test under wine.
>
> I've looked at your file, and it is not related to external
> libraries nor the luatex extensions at all: The problem is the
> \immediate\pdfximage.
>
> You can get the exact same problem in pdftex with this input:
>
> \pdfoutput=1
> \immediate\pdfximage width 0.5\hsize {./cow.pdf}
> \pdfrefximage\pdflastximage
> \input knuth
> \input knuth
> \input knuth
> \input knuth
> \input knuth
> \input knuth
> \input knuth
> \bye
>
> In both cases, the problem can be fixed by adding a \hbox around
> the \pdfrefximage. But now I have a question for Hartmut: is this
> supposed to happen?

definitely looks like a bug to me

\setuppapersize[A4][A1] \setuplayout[location=middle,marking=on]

\starttext

\immediate\pdfximage  width 0.5\hsize {./cow.pdf}
\dorecurse {3}{\pdfrefximage\pdflastximage}
\dorecurse{10}{\the\pagetotal\input knuth \par}

\stoptext

the ref'd image whatsit is added to the mvl but the height is not added
to pagetotal (at least that's what it looks like) due the fact that no
paragraph is started

i assume that this bug went unnoticed as macropackages put such material
normally in a box

i'm not sure if it's the parbuilder or the page builder .. another test:

\dorecurse {5}{\pdfrefximage\pdflastximage x\par}

(i can do some more testing tommorrow)

Hans

-----------------------------------------------------------------