[tex-live] Fontspec overriding default paper size with LuaTeX

[Joseph Wright]

On 26/05/2016 15:00, Norbert Preining wrote:
> Hi David
> 
>> so far it looks like expected behaviour, I don't see a bug.
>>
>> \documentclass{article}
>>
>> specifies a USletter document and (once you load a package that knows
>> anything about the back end) that is what you are getting.
> 
> That hasn't been the behaviour since many years.
> 
> We allowed for setting the global paper size so that documents without a paper specification got that paper size.
> 
> This is broken now, and I consider this very unfortunate.
> 
> Norbert

Hi Norbert,

I think there is a misunderstanding here as there are two essentially
independent places paper size come in.

>From the driver point of view there's the physical size of the paper.
LaTeX2e itself doesn't attempt to set this as there was no common
mechanism in the early 1990s for this. Values are set by graphics for
dvips, etc., and in direct PDF output mode some decision has to be made
about paper size so it's also set there.

There's then the layout that is being targeted from the macro level. The
LaTeX2e kernel defaults to letter paper with an assumption that the
result will be printed on something appropriate. This means that

    \documentclass{article}
    \begin{document}
    Hello
    \end{document}

has the wrong margin values for A4 paper irrespective of what the driver
end does. You therefore *have* to have

    \documentclass[a4paper]{article}

or a package-based equivalent to get that right.

Various packages do try to bring the two concepts together, most notable
geometry.

Joseph