[4.0] 包围盒计算错误，导致 shape 绘制不出来

[simaQ]

当 arc path 的起始点和结束点相同时（示例中的 path1），shape 无法绘制。

复现 demo: http://riddle.alibaba-inc.com/riddles/f24a3dda

将局部刷新关闭就 OK，目前来看是因为 path1 的 bbox 计算有问题。

[antv-bot]

Translation of this issue:

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[4.0] The calculation of the bounding box is incorrect and the shape cannot be drawn

When the start and end points of the arc path are the same (path1 in the example), the shape cannot be drawn.

Reappear demo: http://riddle.alibaba-inc.com/riddles/f24a3dda

It is OK to turn off the partial refresh. At present, it is because there is a problem with the bbox calculation of path1.