guile accepts invalid complex number syntax

[Bruno Haible]

Seen with guile-1.6.4:

$ guile
guile> 1.2+3.4+0ii
1.2+3.4i

This should be parsed as a symbol, not as a number (according to
r5rs.info node "Lexical structure").

Here is an (untested) suggestion for a fix.

*** libguile/numbers.c  2005-01-16 15:58:44.000000000 +0100
--- libguile/numbers.c.new      2005-01-16 16:34:37.000000000 +0100
***************
*** 2401,2407 ****
  }
  
  SCM
! scm_istr2flo (char *str, long len, long radix)
  {
    register int c, i = 0;
    double lead_sgn;
--- 2401,2407 ----
  }
  
  SCM
! scm_istr2flo (char *str, long len, long radix, int allow_complex)
  {
    register int c, i = 0;
    double lead_sgn;
***************
*** 2429,2435 ****
    if (i == len)
      return SCM_BOOL_F;                /* bad if lone `+' or `-' */
  
!   if (str[i] == 'i' || str[i] == 'I')
      {                         /* handle `+i' and `-i'   */
        if (lead_sgn == 0.0)
        return SCM_BOOL_F;      /* must have leading sign */
--- 2429,2435 ----
    if (i == len)
      return SCM_BOOL_F;                /* bad if lone `+' or `-' */
  
!   if (allow_complex && (str[i] == 'i' || str[i] == 'I'))
      {                         /* handle `+i' and `-i'   */
        if (lead_sgn == 0.0)
        return SCM_BOOL_F;      /* must have leading sign */
***************
*** 2636,2641 ****
--- 2636,2644 ----
    if (i == len)
      return scm_make_real (res);
  
+   if (!allow_complex)
+     return SCM_BOOL_F;
+ 
    if (str[i] == 'i' || str[i] == 'I')
      {                         /* pure imaginary number  */
        if (lead_sgn == 0.0)
***************
*** 2656,2662 ****
      case '@':
        {                               /* polar input for complex number */
        /* get a `real' for scm_angle */
!       second = scm_istr2flo (&str[i], (long) (len - i), radix);
        if (!SCM_SLOPPY_INEXACTP (second))
          return SCM_BOOL_F;    /* not `real' */
        if (SCM_SLOPPY_COMPLEXP (second))
--- 2659,2665 ----
      case '@':
        {                               /* polar input for complex number */
        /* get a `real' for scm_angle */
!       second = scm_istr2flo (&str[i], (long) (len - i), radix, 0);
        if (!SCM_SLOPPY_INEXACTP (second))
          return SCM_BOOL_F;    /* not `real' */
        if (SCM_SLOPPY_COMPLEXP (second))
***************
*** 2675,2681 ****
    if (i == (len - 1))
      return scm_make_complex (res, lead_sgn);
    /* get a `real' for imaginary part */
!   second = scm_istr2flo (&str[i - 1], (long) (len - i), radix);
    if (!SCM_INEXACTP (second))
      return SCM_BOOL_F;                /* not `ureal' */
    if (SCM_SLOPPY_COMPLEXP (second))
--- 2678,2684 ----
    if (i == (len - 1))
      return scm_make_complex (res, lead_sgn);
    /* get a `real' for imaginary part */
!   second = scm_istr2flo (&str[i - 1], (long) (len - i), radix, 0);
    if (!SCM_INEXACTP (second))
      return SCM_BOOL_F;                /* not `ureal' */
    if (SCM_SLOPPY_COMPLEXP (second))
***************
*** 2748,2754 ****
        if (!SCM_FALSEP (res))
        return res;
      case 2:
!       return scm_istr2flo (&str[i], len - i, radix);
      }
    return SCM_BOOL_F;
  }
--- 2751,2757 ----
        if (!SCM_FALSEP (res))
        return res;
      case 2:
!       return scm_istr2flo (&str[i], len - i, radix, 1);
      }
    return SCM_BOOL_F;
  }