Multi-level membership inheritance causes bin/UpdateMembershipRecord to produce duplicate membeships

If membership is inherited through more than one level, the next run of bin/UpdateMembershipRecord creates duplicate memberships.

For example, suppose a membership organization "National". Organization "State" is a member of "National". Organization "Chapter" has a relationship with "State" that causes it to inherit membership from "National". Individual "Jane Member" has a relationship with "Chapter" that causes her to inherit membership from "Chapter". So far, so good. Then cron script bin/UpdateMembershipRecord runs. After that, "Jane Member" has two (duplicate) memberships. Additional runs of the script causes a cascade of damage.

The attached Selenium (http://seleniumhq.org) script produces this result in 2.1.6 with 100% reproducibility.

Eliminating multi-level membership inheritance is not likely to be a good answer since it's useful.

Cheers – Walt