[XeTeX] Seemingly inexplicable shift in page origin between TL 2014 and TL 2016

[Bruno Le Floch]

On 7/12/16, Philip Taylor <P.Taylor at rhul.ac.uk> wrote:
> I have just installed TeX Live 2016 for the first time, using the "small"
> scheme and a couple of additional options, but I find when I try to
> re-generate /The Oral History of Horsmonden/ that the entire page image has
> been displaced vertically upwards by about 1 true in.  I append the code
> that does the necessary computation of dimensions, and wonder whether anyone
> can identify what has changed between the two releases.
>
> % !TeX Program=XeTeX
> % !TeX Root = Oral-History.TeX
>
> \magnification 1000
>
> \special {pdf: docview << /PageLayout /TwoPageRight >>}
> \special {pdf: docview << /OpenAction [0 /Fit] >>}
>
> \newdimen \innermargin
> \newdimen \outermargin
> \newdimen \uppermargin
> \newdimen \lowermargin
> \newdimen \cropwidth
> \newdimen \cropheight
> \newdimen \cropmark
> \newdimen \cropmitre
> \newdimen \Knuthoffset
>
> \innermargin = 0,618 true in
> \outermargin = 1,0 true in
> \uppermargin = \dimexpr (\innermargin + \outermargin) / 2 \relax
> \lowermargin = \uppermargin
> \Knuthoffset = 1 in
>
> \def \imagepath {}
>
> \hsize = 176 true mm
> \vsize = 250 true mm
> \ifcropmarks
>     \pdfpagewidth = 210 true mm
>     \pdfpageheight = 297 true mm
> \else
>     \pdfpagewidth = \hsize
>     \pdfpageheight = \vsize
> \fi
> \advance \hsize by -1.618 true in
> \advance \vsize by -1.618 true in
> \parindent = 0 pt
>
> \advance \hoffset by \dimexpr -0.382 true in / 2 \relax
> \advance \voffset by \dimexpr -0.382 true in / 2 \relax
>
> \ifcropmarks
>     \advance \hoffset by \dimexpr (210 true mm - 176 true mm) / 2 \relax
>     \advance \voffset by \dimexpr (297 true mm - 250 true mm) / 2 \relax
> \fi
>
> \ifcropmarks
>     \input Cropmarks
>     \rvcropmarkstrue
>
>     \rectotopcropmark = \dimexpr 1.618 true in / 2 \relax plus 1 cm minus -1
> mm
>     \rectobottomcropmark = \dimexpr 250 true mm - \rectotopcropmark \relax
> plus 1 cm minus -1 mm
>     \rectoleftcropmark = 0,618 true in plus 1 cm minus -1 mm
>     \rectorightcropmark = \dimexpr 176 true mm - \rectoleftcropmark  \relax
> plus 1 cm minus -1 mm
>
>     \versotopcropmark = \rectotopcropmark
>     \versobottomcropmark =\rectobottomcropmark
>     \versoleftcropmark = 1,0 true in plus 1 cm minus -1 mm
>     \versorightcropmark = \dimexpr 176 true mm - \versoleftcropmark  \relax
> plus 1 cm minus -1 mm
> \fi
>
> *\advance \voffset by 1 true in % REQUIRED ONLY F**OR **TL 2016*
>
> --
>
> Philip Taylor
>

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l.29 \ifcropmarks

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