when ido-mode is enabled.
ffap on any file will trigger a argument mismatch error.

step to reproduce the bug:
on emacs source directory. build emacs.
run 'src/emacs -nw -q'
M-x ido-mode
M-x eshell
ls
C-p
ffap

got error: 'Wrong number of arguments: (0 . 0), 1'


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