[Rd] Plotmath on Fedora 31 broken with with pango >= 1.44 - workarounds?

[Paul Murrell]

Hi

The R branch ...

https://svn.r-project.org/R/branches/R-symfam/

... is now set up so that it works "out of the box" on Fedora by setting 
the default to be 'symbolfamily=cairoSymbolFont(family, usePUA=FALSE)' 
when grSoftVersion()["pango"] is greater than "1.44".

This means that on Fedora 31 (at least on the Docker container I am 
testing on) "sans"->"NimubusSans" is used as the symbol font by default 
and R converts Adobe Symbol Encoding code points to non-PUA UTF8 code 
points.  This is not the prettiest result, but it is a lot better than 
the page full of missing glyphs that we had.

The default on less "bleeding edge" systems, e.g., my Ubuntu 18.04, 
remains 'symbolfamily="Symbol"'.

The default on other platforms is supposed to be the same as it was, but 
I need help to confirm that.  I have set up a github repo ...

https://github.com/pmur002/R-symfam-testing

... that describes how to test this on macOS and Windows if anyone has 
time to do so.

I will start trying to set up a Windows test unless someone beats me to it.

Paul

On 30/03/20 3:24 pm, Paul Murrell wrote:
> Hi
> 
> I have created an R branch that contains a potential fix ...
> 
> https://svn.r-project.org/R/branches/R-symfam/
> 
> This allows, for example, ...
> 
> cairo_pdf(symbolfamily="OpenSymbol")
> 
> ... to specify that the OpenSymbol family should be used as the "symbol" 
> font (e.g., for "plotmath") in R.
> 
> This is just a separate branch for now because, while I have tested it 
> under Unbuntu 18.04 and Fedora 31, I cannot even build R for Windows 
> (right now) or Mac (ever) and I do not want to drop a bomb on R-devel at 
> this stage of the release process for R 4.0.0.
> 
> The attached file contains at least an outline of steps required to do a 
> minimal test if anyone wants to try the fix on Linux.
> 
> cc'ing Simon and Jeroen in case they are able to help with checking that 
> this builds and works on Mac and/or Windows.
> 
> NOTEs:
> - 'symbolfamily' can only be specified when a graphics device is opened, 
> and it is then fixed for that device.
> - on Windows, for cairo-based devices, the "symbol" font is still 
> hard-coded as "Standard Symbols L"
> 
> Paul
> 
> On 30/03/20 8:15 am, Paul Murrell wrote:
>> Hi
>>
>> Thanks for your input on this Iñaki and Nicolas.
>>
>> I am starting testing an R fix for this problem today.
>>
>> As suggested, the plan is to allow the R user to specify a font family 
>> other than "symbol" for plotmath output (or, more generally, in R 
>> parlance, for 'font=5' or 'fontface=5') on a Cairo-based graphics device.
>>
>> Paul
>>
>>
>> On 27/03/20 11:30 pm, Iñaki Ucar wrote:
>>> On Wed, 25 Mar 2020 at 12:25, Nicolas Mailhot
>>> <nicolas.mailhot using laposte.net> wrote:
>>>>
>>>> <snip>
>>>>
>>>> R brought this all on itself by hardcoding a Windows-only “Symbol” font
>>>> family name in its default conf. Linux systems are UTF-8 by default for
>>>> ~20 years now, they don’t need the forcing of magic font families to
>>>> handle symbols not present in the 8-bit legacy Windows encodings.
>>>>
>>>> The actual effect of this conf is not the selection of font files with
>>>> special and unusual symbols. It is to priorize fonts that match the
>>>> "Symbol" magic name. And those fonts are few and crumbling on Linux
>>>> systems, because no one has needed to bother with them since Linux
>>>> switched to UTF-8 last millenium.
>>>>
>>>> Just stop using “Symbol” in R and things will work a lot better.
>>>> Alternatively, prepare to maintain the “Symbol” aliasing stack in
>>>> fontconfig (and fight with wine for it), because *no* *one* *else*
>>>> *cares* about this legacy Windows-specific stuff.
>>>
>>> So, in the light of Nicolas' input (thanks!), I think that font
>>> selection should be fixed upstream in R. I'd be happy to put all this
>>> together in R's bugzilla, but I don't have an account. Could someone
>>> please invite me?
>>>
>>> Iñaki
>>>
>>> ______________________________________________
>>> R-devel using r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>>
> 

-- 
Dr Paul Murrell
Department of Statistics
The University of Auckland
Private Bag 92019
Auckland
New Zealand
64 9 3737599 x85392
paul using stat.auckland.ac.nz
http://www.stat.auckland.ac.nz/~paul/