remove 1/2 in branch AFS: closes #2925

[petrelharp]

Note also the (fairly cursory) tests that (a) fold(branch AFS) == (branch AFS, unpolarised) and (b) the same is true for site AFS with infinite-sites.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.63%. Comparing base (308f67e) to head (2175169).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2933   +/-   ##
=======================================
  Coverage   89.63%   89.63%           
=======================================
  Files          29       29           
  Lines       30170    30174    +4     
  Branches     5864     5873    +9     
=======================================
+ Hits        27042    27046    +4     
  Misses       1789     1789           
  Partials     1339     1339           

Flag	Coverage Δ
c-tests	86.20% <ø> (+<0.01%)	⬆️
lwt-tests	80.78% <ø> (ø)
python-c-tests	88.72% <ø> (+<0.01%)	⬆️
python-tests	99.03% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
c/tskit/trees.c	90.42% <ø> (-0.01%)	⬇️

... and 2 files with indirect coverage changes

[petrelharp]

I think this is ready to go!

[jeromekelleher]

LGTM - we should update the CHANGELOG though, or we'll forget.

[petrelharp]

Done. I see codecov is still weird, but I think it's safe to merge this.

[jeromekelleher]

Yep, happy to merge.

What's going on with the cache thing in MacOS @benjeffery?

[petrelharp]

It seems to be lowering coverage slightly because it's just reduced the denominator. I'll let you hit merge, since I'm not sure if merging PRs where CI failed has undesired effects?

[benjeffery]

Looks like something has changed in the osx base image? Will look into it.

[benjeffery]

Done. I see codecov is still weird, but I think it's safe to merge this.

Note that #2931 is ongoing.

[jeromekelleher]

Let's try rebasing this again when #2935 and #2937 are through - hopefully we'll start getting reliable green-lights from CI again and we can start getting PRs through more easily.

[benjeffery]

@Mergifyio rebase

[mergify]

rebase

✅ Branch has been successfully rebased