`i_gcd()` does not work for `MRB_INT_MIN`.
MODIFY
mrbgems/mruby-rational/src/rational.c
mrbgems/mruby-rational/src/rational.c
@@ -156,10 +156,10 @@ rational_new_i(mrb_state *mrb, mrb_int n, mrb_int d)
if (d == 0) {
rat_zerodiv(mrb);
}
- a = i_gcd(n, d);
- if ((n == MRB_INT_MIN || d == MRB_INT_MIN) && a == -1) {
+ if (n == MRB_INT_MIN || d == MRB_INT_MIN) {
rat_overflow(mrb);
}
+ a = i_gcd(n, d);
return rational_new(mrb, n/a, d/a);
}

`i_gcd()` does not work for `MRB_INT_MIN`.