Can't Reverse Sink Below 15 MP

[Repinuj]

Seen on Seventh.

Could not reverse an Arcane Sink, while having plenty of AP and 14 MP. The button was greyed out, alongside the buttons for generating a new Sink or Well.

Was able to reverse it after the next AP tick, once he had 15 MP. It only deducted 8 MP from the mana pool, as it should.

[Repth]

Ugh yeah, these have been fiddly since inception, basically. I've brought attention to it before, and even tried to figure it out myself to no avail. Hopefully the timing is right this time and some code ninja can figure out where things went wrong in the code.