id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,difficulty 823,arithmetic-shift fails in extreme cases,sjamaan,,"I don't know whether it's worth the trouble to fix this, but I'll put it on here so at least it's documented. {{{(arithmetic-shift -123 most-negative-fixnum) => -123}}} This should be {{{-1}}}. It fails because in chicken.h the {{{C_i_fixnum_arithmetic_shift}}} function calls {{{C_fixnum_shift_right}}} with the negated value of the shift amount. This overflows and wraps around to zero. Fixing it would be simplest by just inlining the shift and negating _after_ unboxing. This is easy, but there are some other places that call {{{C_fixnum_shift_right}}} in this way. This code is obviously wrong but I'm not sure it's worth fixing, since it's such an extreme edge case (if you subtract 1 from the shift amount you get an error that the argument is not a fixnum). On the other hand, not fixing it just seems, I dunno... lazy and possibly dangerous. :)",defect,closed,minor,4.10.0,core libraries,4.7.x,fixed,"edge cases, numbers, shifting, overflow",,