Basic d3shape.arc() broken by recent patch

[jeremybalog]

I believe this fix has created a new issue: https://github.com/d3/d3-shape/commit/52e069b4cefee5b3eba25a3318eba48765d43334

Everything was working perfectly fine previously, but now our code is producing errors. Consider the following code:

const radians = 5.7
const arc = d3shape.arc()
      .startAngle( 0 )
      .endAngle( d => {
        return radians
      })
      .innerRadius( d => {
        return 70 - ( d.index * 20 )
      })
      .outerRadius( d => {
        return 90 - ( d.index * 20 )
      })
      .cornerRadius( 10 )

We can all agree that there are 2 * Math.PI = ~6.28 radians in a circle. By changing the radians variable, this is the output of the arcs:

const radians = 5.7

const radians = 5.8

const radians = 5.9

const radians = 6.0

const radians = 6.1

const radians = 6.2

const radians = 6.3

[mbostock]

Confirmed present since 1.2.3.

[mbostock]

Fixed in d3-shape@1.3.4, d3@5.8.1. Thanks for the report.