When working with cells and views, it's important to remember that the
connections between cells and views are not simple. :)
In particular, a single cell might be shared by multiple views, so a
cell does not have any defined "control view" (except when it's inside
a
-...inView: call, and even then there are some interesting reentrancy
issues). Thus, adding a new supercell ivar is almost certainly wrong.
-performClick: is ugly in that it doesn't properly handle this.
-performClickWithFrame:inView: seems like a much better replacement, so
I'm in favor of adding it and deprecating [NSCell -performClick:].
NSCell.h.patch