typo in sprintf format string segfaults R

typo as simple as %S instead of %s segfaults R devel:
  

not exactly:

    sprintf('%S', 'aa')
    # error: unrecognised format at end of string

without a segfault.  but with another format specifier behind, it will
cause a segfault.

interestingly, here's again the same problem i have reported recently: 
that you are given a number of options for how to leave the session, but
you can type ^c and stay in a semi-working session.  (and the next
execution of the above will  then cause a segfault with immediate exit.)

vQ