kangax/fabric.js — pull request #1715 by asturur (2014-09-30 20:34:16+00:00)
Title: Flippyng y by scaling x and viceversa

When we resize an object by X or by Y we do not scale by the other dimension.
But if we go in direction of flipping it, we may flip it even on the dimension we are not resizing.

It looks a weird behaviour because you see the object suddendly flip with no intermediate state.

You can check on kitchensink.