[Chicken-hackers] Bug in number->string

[Peter Danenberg]

There's appears to be a bug in the way number->string handles
negatives in binary, octal and hexadecimal mode; for instance:

  (string->number (number->string -1 2) 2) => 1.84467440737096e+19

According to r5rs 6.2.6[1], the following should hold true:

  (let ((number number)
        (radix radix))
    (eqv? number
          (string->number (number->string number
                                          radix)
                          radix)))

however:

  (eqv? -1 (string->number (number->string -1 2) 2)) => #f
  (eqv? -1 (string->number (number->string -1 8) 8)) => #f
  (eqv? -1 (string->number (number->string -1 10) 10)) => #t
  (eqv? -1 (string->number (number->string -1 16) 16)) => #f

Footnotes: 
[1]  http://schemers.org/Documents/Standards/R5RS/HTML/r5rs-Z-H-9.html#%_idx_350