Can't define articulation using staccatissimo

[Sven Axelsson]

For some reason I can't define my own articulations using the staccatissimo
symbol. Any other symbol works. 

\version "2.7.10"

#(define my-script-alist
       (append 
         '(("accent-french" .
           ((script-stencil . (feta . ("staccatissimo" . "staccatissimo")))
           (direction . 1) )) 
          )
        default-script-alist) )
        
\layout { \context { \Score scriptDefinitions = #my-script-alist } }
accent = #(make-articulation "accent-french")

\relative c'' { a b\accent c }

This will run with no errors in the log, but also with no articulation markup
in the output. Change "staccatissimo" to e.g. "thumb" and the symbol appears
correctly. Bug?

-- 
Sven Axelsson