IndexError in memlet propagation

[edopao]

During integration of dace in icon4py, it was found that SDFG transformations fail in memlet propagation:

>       propagate_memlets_sdfg(sdfg)

tests/memlet_propagation_test.py:169: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
dace/sdfg/propagation.py:1162: in propagate_memlets_sdfg
    propagate_memlets_state(sdfg, state)
dace/sdfg/propagation.py:1205: in propagate_memlets_state
    propagate_memlets_nested_sdfg(sdfg, state, node)
dace/sdfg/propagation.py:1084: in propagate_memlets_nested_sdfg
    border_memlet.src_subset[i] = fallback_subset[i]
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = Range (0:dim_X), key = 1

    def __getitem__(self, key):
>       return self.ranges.__getitem__(key)
E       IndexError: list index out of range

The type of SDFG causing this issue is reproduced in a test case in PR #1480, here is a picture:

PR #1480 is applying a workaround in dace/sdfg/propagation.py, to make the test pass. However, this does not seem to be the proper the solution. This code change is rather a placeholder to highlight where the issue originates.

[edopao]

Not an issue in memlet propagation, the problem was in the test SDFG. As pointed by @philip-paul-mueller, the memlet that performed the actual slicing was going from _out to _inp, i.e. in the wrong direction.