@richard
Running:
import torch
from torch.autograd import Variable

a = Variable(torch.randn(5))
a[[-1, 0]]

Results in an error:
    a[[-1, 0]]
  File "/usr/local/lib/python2.7/dist-packages/torch/autograd/variable.py", line 78, in __getitem__
    return Index.apply(self, key)
  File "/usr/local/lib/python2.7/dist-packages/torch/autograd/_functions/tensor.py", line 87, in forward
    result = i.index(ctx.index)
RuntimeError: index out of range at /pytorch/torch/lib/TH/generic/THTensorMath.c:277