Inconsistency in rounding between inner and outer edge of input focus rings

[robertknight]

Input elements have focus rings that are rounded on the outside but square on the inside. This feels inconsistent next to other elements such as buttons which have focus rings that are rounded on both sides.

Button:

Input:

Input, zoomed in:

[robertknight]

It was pointed out in this Slack thread that the inner corners are technically rounded, but due to the way the inner rounding is calculated, the visual effect is that it looks square.