footnote and xcolor do not commute

[hseg]

MWE:

---
header-includes: \usepackage{xcolor}
...
----
C^[F]
----

LaTeX complains of a forgotten \endgroup. A bit of digging shows that this is due to footnote defining \fn@endnote with a dependency on \color@endgroup, which is subsequently redefined by xcolor, breaking the macro.

This in turn breaks any document that uses footnotes and xcolor. Since tikz depends on xcolor, adding it to header-includes also triggers this problem.

A quick-and-dirty workaround until footnote fixes this is to include xcolor before footnote.
Subsequent inclusions will note it's already included and not run.
Note that xcolor is in texlive-latex-recommended, so this shouldn't be an issue.

P.S. I will note, however, that footnote was last updated in 1996, so I'm not holding my breath for it to be fixed. Haven't contacted upstream, but seeing as this is a well-known bug that's at least 7 years old, they're probably not responding.

[jgm]

Note: the default template loads xcolor if colorlinks is set to a true value.
This happens before footnote is loaded, so we should be okay unless you manually include xcolor. To avoid manually loading xcolor, you could always set colorlinks to true (you could set all the colors to black).

I don't see anything that needs to be changed in pandoc here, do you?

[hseg]

Will try out the `colorlinks=true` suggestion later today. If it works, then technically we don't need to change anything besides the documentation. BTW, I'm not manually including `xcolor`. As previously noted, it is pulled in by `tikz`. I wouldn't be surprised if other packages pull it in as well.

…

On 30 August 2018 0:45:52 GMT+03:00, John MacFarlane ***@***.***> wrote: Note: the default template loads `xcolor` if `colorlinks` is set to a true value. This happens before `footnote` is loaded, so we should be okay unless you manually include `xcolor`. To avoid manually loading xcolor, you could always set `colorlinks` to true (you could set all the colors to `black`). I don't see anything that needs to be changed in pandoc here, do you? -- You are receiving this because you authored the thread. Reply to this email directly or view it on GitHub: #4861 (comment)

-- Sent from my Android device with K-9 Mail. Please excuse my brevity.

[adunning]

In theory there shouldn't be much harm in loading xcolor whether or not the colorlinks option is enabled; there are very few packages that don't take it into account.

[adunning]

A cleaner solution might be to remove the footnote package, which we're only using to fix footnotes in tables. It appears from https://texfaq.org/FAQ-footintab that this is already fixed by using longtable, and I haven't been able to find any examples of footnotes in tables as generated by Pandoc that require it. Are there perhaps more complex examples that require it?

[adunning]

Ah, the reason for the inclusion of footnote can be found in #2378.

[jgm]

Well, I guess we could just load xcolor unconditionally. Do you want to submit a PR? The html templates (and slide show templates) would have to be changed, and the tests updated.

[adunning]

Yes, I will research it more to make sure there aren't any obvious conflicts and send something in.