Maintain snapping behaviour even with a mirror modifier attached

Currently, adding a mirror modifier to an object will change how it snaps to targets. Normally, snapping causes the closest part of the object to line up with the target, but once a mirror modifier is applied this behaviour changes so that the furthest part of the object lines up with the target. This causes significant overlap with the target, which goes against how snapping is generally used.

Removing the modifier, or turning off 'realtime display', immediately resumes normal snapping behaviour.

This behaviour is very consistent, and occurs in both 4.2.2 LTS and 4.5.1 LTS, so I assume its a result of some internal logic of the mirror modifier, rather than being an outright bug.

I believe this should be changed so that snapping behaviour remains consistent regardless of any mirror modifiers.

Snapping normally:

Snapping with a mirror modifier across the X axis, with the larger cube as the mirror object: