Too many spaces in deparsed complex numbers with digits17 control option

Richard Cotton <richierocks at gmail.com>
    on Thu, 5 May 2016 09:37:42 +0300 writes:

If you set the "digits17" control option in deparse, you get a lot of
unnecessary space in the representation of complex numbers.

deparse(0 + 0i)

[1] "0+0i"

deparse(0 + 0i, control = "digits17")

[1] "0 +                 0i"

As far as I can tell, the logic for this comes from this piece of
/src/main/deparse.c:

if (TYPEOF(vector) == CPLXSXP && (d->opts & DIGITS16)) {
  Rcomplex z =  COMPLEX(vector)[i];
  if (R_FINITE(z.r) && R_FINITE(z.i)) {
      snprintf(hex, 64, "%.17g + %17gi", z.r, z.i);
      strp = hex;
  } else
      strp = EncodeElement(vector, i, quote, '.');
}

I think this is a small bug, and that "%17gi" in the snprintf call
ought to be "%.17gi".

Also there shouldn't be any space around the plus sign for consistency
with the non-digits17 option.

Is this a real bug, or is it deliberate behaviour?

-- 
Regards,
Richie