Segfault on buffers with non-trivial strides

[mhasself]

Instantiating G3Timestream from a numpy array works, but only if the buffer is close-packed in memory. Passing a view into an array, where strides are not 1, yields a segfault.

import spt3g
from spt3g import core
import numpy as np

print(spt3g.version.gitrevision)

for n in [1, 2, -2]:
    print(n)
    data = np.zeros(100, 'float64')[::n]
    print(core.G3Timestream(data))

Results in:

c45570b13da0cdaaab0b519344892d5053f99b20
1
100 samples at inf Hz
2
Segmentation fault (core dumped)

Expected result: the non-trivial stride should either quietly work, or raise an exception.

[arahlin]

Does this fix it?

diff --git a/core/src/G3Timestream.cxx b/core/src/G3Timestream.cxx
index 62d5c40..84fec55 100644
--- a/core/src/G3Timestream.cxx
+++ b/core/src/G3Timestream.cxx
@@ -967,6 +967,7 @@ timestream_from_iterable(boost::python::object v,
                PyBuffer_Release(&view);
        } else {
                PyErr_Clear();
+               x = G3TimestreamPtr(new G3Timestream());
                boost::python::container_utils::extend_container(*x, v);
        }

[mhasself]

It fixes the segfault but now I see random data:

for n in [1, 2, -2]:
    print(n)
    data = np.zeros(100, 'float64')[::n]
    ts = core.G3Timestream(data)
    print(ts[0], ts[1])

Output:

1
0.0 0.0
2
4.6811727725461e-310 4.68117277256586e-310
-2
4.68117272068817e-310 4.68117272070794e-310