[groff] Macron characters in pdf files

[Peter Schaffter]

Greetings.

I've verfied that the problem discussed in the following forwarded
email exists.  -Tps has no trouble finding macron characters
composed in vim; -Tpdf does.  Deri, I think this is your bailiwick.
:)

----- Forwarded message -----

Date: Mon, 4 Jun 2018 15:07:35 -0400
To: address@hidden
From:
Subject: groff and mom - macrons in pdfs

Greetings good Sir and thank you for MOM!

I'm writing today because I cannot seem to overcome an issue where I am unable 
to get macrons over vowels to display correctly in the resulting pdfs.
I am on Arch linux using vim as my text editor.
Groff version 1.22.3-7 is installed. 
I use Atril to display pdfs.
I can write in Libreoffice Writer and enter the macron-vowels thru the charcter 
selector, then export to pdf and the characters display correctly
so I have fonts installed sufficient to display the macron characters.
I can enter the macron-vowels in vim using the Ctrl-K diagraph keybindings and 
they display correctly in the terminal.
If I export the .mom file to ps the result, whilst ugly, displays the 
macron-vowels correctly, so I believe somewhere in groff something is going 
wrong.
What I am getting in the pdf is the Capital A with strange markings in place of 
the i or o with macron intended.
I found online a groff macro .AM which claims to be able to produce macron 
characters, but I do not see how to incorporate this with mom.
I also tried \[i-] style with no luck.
I get "can't find special character" errors with this method.
Trying e.g. \[34] and \[de] works, but the macron does not seem to work.
Please tell me, is this missing funcionality or am I missing something in the 
documentation on how to produce macron-vowels with mom?

I thank you again for all the hard work you have done to create mom - I do not 
want to have to use Libreoffice Writer or another piece of software.
I love mom, but need to learn how to overcome obstacles such as this one.

Steve Philipp

----- End forwarded message -----

-- 
Peter Schaffter
http://www.schaffter.ca