frac -0x80..00 / 0x80..00

[Kevin Ryde]

I think scm_make_ratio is missing one case of an integer result,
namely when the numerator is most-negative-fixnum and the denominator
is the negative of that (as a bignum).  Viz,

        (integer? (/ -536870912 536870912))
        => #f

where I would expect #t.  (Attempting to actually print that division
seems to go into an infinite recursion in number->string.)

        * numbers.c (scm_make_ratio): Check for numerator equal to
        SCM_MOST_NEGATIVE_FIXNUM and bignum denominator the negative of that,
        giving integer -1.

        * tests/fractions.test: Exercise most-negative-fixnum over -ve of
        most-negative-fixnum.

numbers.c.make-frac.diff
Description: Text document

fractions.test.most-neg.diff
Description: Text document