[Libmesh-devel] PointLocatorTree bug affecting PeriodicBoundaries?

[Roy S. <roy...@ic...>]

While regression testing some recent changes I hit on what seems to be
a long-standing bug: ex24 fails in debug mode on my systems when run
on 4 processors.  It's been passing continuous integration checks on 1
proc and it passes 2 proc checks, and the bug seems to have existed
but gone unnoticed for as long as ex24 has existed.

On first investigation it looks like the problem is with
PointLocatorTree: searching for a periodic neighbor should always
produce an active element, but for some reason the tree is coming back
with a parent element.  I probably won't have time to look into this
further until next week, so in the meantime I thought I'd give a
warning to anyone who's actively using periodic BCs (or even just
point_locator()) in parallel.
---
Roy