Stroke is broken for multiple subpaths per shape layer

Red is an example of multiple open-ended subpaths in a single shape layer.
Green is an example of a single open-ended subpath in a single shape layer.

As you can see: multiple sub-paths completely break dashing.

This may be related to another issue:

Upper version is a single open-ended sub-path on a single shape layer
Lower version are two open-ended sub-paths on a single shape layer. The shapes seems to act as though it were closed, however: it's not actually closed. There are no edges linking the end vertices of that path, and likewise, the triangle is constructed of 3 verts and 2 edges - the bottom-right edge shouldn't exist.