What is the optimal topology for a base with square corner meeting a cylinder? I would like to make this part:



This is my approach:



In order for the inner edge loops not go all the way to the cylinder, I cut the quad into two triangles. Like this:



But after adding loop cuts, the model still suffers from some pinching. 



How can I fix this shading issue? And what is the optimal topology for this shape?

This is my blend file if necessary: Blend File
This topology seems to work fine, no visible pinching if you move the vertex a bit: