In the meantime, here's one:

  regehr@home:~/volatile/bugs/tmp007$ cparser --version
  cparser (0.9.11) using libFirm (1.18)
  This is free software; see the source for copying conditions.  There is NO
  warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

  regehr@home:~/volatile/bugs/tmp007$ cparser -c small.c
  cparser: ast2firm.c:3197: conditional_to_firm: Assertion `get_irn_mode(false_val) == mode' failed.
  Aborted
  regehr@home:~/volatile/bugs/tmp007$ cat small.c
  unsigned char foo (int ui1, unsigned char ui2)
  {
    return ui2 ? : ui1 + ui2;
  }

Well, that isn't valid C99 or even C89. It's yet another GNU extension to support. Thanks for the report, though!

BTW the bug is fixed in the repository version.