is Array#pack supposed to truncate integers in 1.9?

Surely this is a bug, not a feature?

% ./ruby1.9.x -e 'p [0xffffffff].pack("i")'
"\377\377\377\377"
% ./ruby1.9.x -e 'p [0xffffffffff].pack("i")'
"\377\377\377\377"
% ./ruby1.9.x -e 'p [0xffffffffffff].pack("i")'
"\377\377\377\377"

I would expect every one of these to fail, 0xffffffff is outside the
range of numbers representable as a signed 32-bit integer, and none of
those transformations are reversible:

% ./ruby1.9.x -e 'p [0xffffffff].pack("i").unpack("i")'
[-1]
% ./ruby1.9.x -e 'p [0xffffffffff].pack("i").unpack("i")'
[-1]
% ./ruby1.9.x -e 'p [0xffffffffffff].pack("i").unpack("i")'
[-1]


The last two are a change in behaviour from ruby1.8.5:

ruby1.8.5 -e 'p [0xffffffffff].pack("i")'
-e:1:in `pack': bignum too big to convert into `unsigned long'
(RangeError)


This seems a misfeature to me that seems likely to cause hard to track
down bugs.

Cheers,
Sam

% ruby1.8.5 --version
ruby 1.8.5 (2007-02-14 patchlevel 20) [i686-linux]
% ./ruby1.9.x --version
ruby 1.9.0 (2007-02-21 patchlevel 0) [i686-linux]