Not 100% sure this is a bug or possibly intentional.

A zoom behavior attached to a selection that has an active transition without a name (i.e. null is used) interrupts the transition when translated by e.g. translateBy. If the transition is named, it is not interrupted.

I think this happens on https://github.com/d3/d3-zoom/blobymaster/src/zoom.js#L81. Should it just interrupt transitions named "zoom"?