snappy v1606+ potential bug with "mergePatchFaces off"

I got the following error when setting "mergePatchFaces off" in snappyHexMesh (v1606+):

Merge refined boundary faces
----------------------------

[13]
[13]
[13] --> FOAM FATAL ERROR:
[13] attempted assignment to self
[13]
[13]     From function void Foam::List<T>::operator=(const Foam::List<T>&) [with T = int]
[13]     in file /share/OpenFOAM/OpenFOAM-v1606+/src/OpenFOAM/lnInclude/List.C at line 466.
[13]
FOAM parallel run aborting

When I set "mergePatchFaces on" the problem doesn't occur.

Best regards,

Charlie.