bug#38761: 26.3; reftex-citation-format doesn't know biblatex fields

[Andrew Francis Swann]

For local citations outside a tex file I have

  (setq reftex-cite-format
        "[%4a, \\textit{%t}, %b %e, %u, %r %h %j \\textbf{%v} (%y), %p %<]" )

but when the database file is in biblatex format, the journal name is not in 
the field journal, accessed by %j, but rather in the field journaltitle, that 
is not detected.  E.g. the entry

@Article{Abels:slice,
  author =       {Abels, H.},
  title =        {Parallelizability of proper actions, global
                  {$K$}-slices and maximal compact subgroups},
  journaltitle = {Math. Ann.},
  year =         1974,
  volume =       212,
  pages =        {1--19}
}

produces the local citation 

[Abels, \textit{Parallelizability of proper actions, global {$K$}-slices and 
maximal compact subgroups}, \textbf{212} (1974), 1--19]

with no journal name.

Emacs  : GNU Emacs 26.3 (build 1, x86_64-apple-darwin18.7.0, NS appkit-1671.60 
Version 10.14.6 (Build 18G1012))
 of 2019-11-06
Package: 26.3

current state:
==============
(setq
 window-system 'ns
 reftex-plug-into-AUCTeX t
 )

-- 
Andrew Swann | Associate Professor | Tel +45 871 55767 | address@hidden | 
http://home.math.au.dk/swann/ | Department of Mathematics, Aarhus University, 
Ny Munkegade 118, Bldg 1530, DK-8000 Aarhus C, Denmark | Dept +45 871 50000