[XeTeX] Problem with ifpdf switch

[Zdenek Wagner]

Hi all,

ifpdf.sty is not buggy but in some cases it can trigger bugs
elsewhere. If you do anything more complex, it is better to switch to
iftex.sty.

Zdeněk Wagner
http://ttsm.icpf.cas.cz/team/wagner.shtml
http://icebearsoft.euweb.cz

po 6. 7. 2020 v 20:00 odesílatel David Carlisle <d.p.carlisle at gmail.com> napsal:
>
> I get no spurious output from this document with xetex
>
> \input ifpdf.sty
> \input eplain
>
> xxx
>
> \bye
>
>
> However you do not have the current version of ifpdf.sty your text is showing a 2016 date which presumably means you have an old copy somewhere on a local input path that is masking the one you would have installed with a current installation.
>
>
>
> The current  version of ifpdf.sty as distributed with texlive2020 has the line
>
>   \ProvidesPackage{ifpdf}[2019/10/25 v3.4 ifpdf legacy package. Use iftex instead.]
>
> So will not have made the text that you show.
>
> Some other macro that you have loaded has apparently defined \ProvidesPackage so that instead of sending the final argument to the log it typesets it, but impossible to say what that is from the information posted.
>
> David
>
>
> On Mon, 6 Jul 2020 at 18:31, Julian Bradfield <jcb+xetex at jcbradfield.org> wrote:
>>
>> On 2020-07-06, John Was <johnoxuk at gmail.com> wrote:
>> > On acquiring a new PC I decided to install the latest TeXLive (previously I
>> > was on the 2013 version).  I use plain XeTeX.  To my surprise, the first
>> > page now has at the top the text:
>> >
>> > ifpdf [2016/04/04 v3.0 Provides the ifpdf switch]
>> >
>> > See the attached one-page PDF.
>> >
>> > Below I give some lines from my log file - it's the last line that is of
>> > interest, viz.:
>>
>> No, that's not the line of interest. The lines of interest are all the
>> other files you might have loaded that might cause this breakage.
>> The line you see is, naturally, coming from ifpdf.sty, and to see it,
>> something must have broken the \ProvidesPackage, messed with catcodes,
>> or done something else to cause the break, unless the (rather old)
>> ifpdf.sty itself is buggy, which seems unlikely.
>>
>> Please construct a minimal (non-)working example, and post the full
>> log file, with links to all non-standard files loaded.
>>
>> Unless of course somebody jumps in to say they recognize the problem!