I don't know if this needs to up the C-ABI/API versions or not.

Looks fine to me.

@certik: The background here is that #2694 is going to change the call signature for CreateSortedStridePerm, which is a new public API function in 1.7. But, #694 is too large to backport to 1.7. So this PR makes a minimal matching change to 1.7 so that we won't end up with API breakage or having to make uglier workarounds later.

I set this to milestone 1.7. This looks ok to me too, but given the change, @charris, @rgommers, would you mind giving this an OK as well? After that it can be merged.

@seberg you don't need to update the API/ABI versions. That should be done by the release manager just before a release. For master or unreleased branches you can get a CAPIMismatchWarning during building, but that's not a big deal.

@certik motivation for this PR sounds good. I didn't look at this code in detail, if @njsmith reviewed it that should be enough.

Ok. Where is the API/ABI version? I am only aware of these lines in setup.py:

MAJOR               = 1
MINOR               = 8
MICRO               = 0

I'll wait a little more with the merge, to give others chance to comment. If there are no more objections, I'll merge it tomorrow.

See https://github.com/numpy/numpy/blob/master/doc/HOWTO_RELEASE.rst.txt#check-the-c-api-version-number

First of, what we are talking about here is ie. a 3x1x3 Fortran ordered array, that is put into CreateSortedStridePerm will not be Fortran order any more unless the shape information is used. This does somewhat matter for array creation purpose (I thought that would change when I wrote this, but it probably won't) but not when sorting for speed reasons. So if the array creation is supposed to be all clean, either the shape information needs to stay passed in and probably also added to npy_stride_sort_item (if that is possible) or maybe a new function to clean the strides of 1-dimensional axes created.

I am tending toward just doing it like this PR does and then maybe implementing that extra function later. But if you prefer that CreateSortedStridePerm should sort cleanly right away, I could do a PR for that.

That's fine with me. Since nobody is against, I am merging it now.