Function svn_io_file_open 

pub unsafe extern "C" fn svn_io_file_open(
    new_file: *mut *mut apr_file_t,
    fname: *const c_char,
    flag: apr_int32_t,
    perm: apr_fileperms_t,
    pool: *mut apr_pool_t,
) -> *mut svn_error_t

Wrapper for apr_file_open(). @a fname is utf8-encoded. Always passed flag | APR_BINARY to apr.