P: Stroke automatically closes on layer with multiple open subpaths

Okay i see what your talking about..

For a single path on a shape layer that is not closed the stroke works only on the path, but if you add a subpath that is not closed, then the stroke connects the open parts of the paths so the paths appear closed.

I guess i'm not getting what your seeing.
Could you post a screenshot or short video?

The way I'm seeing the bug is simply that when there's multiple subpaths in a Shape, all subpaths are stroked as if they are closed regardless of being open or closed.

This doesn't seem related to pasting; it happens regardless of how the Shape becomes made of subpaths, e.g. initially drawing a Shape with multiple subpaths, or drawing an additional subpath in an existing Shape, or pasting a path into an existing Shape, or merging Shapes.

We change the title to reflect the contents, and try to keep the topic clear and searchable.
The title was changed based on your original description, and correctly matched how your original description read.

OK, you left too many details out of your original post.

Chris, you've changed the topic of this post incorrectly. Please don't do that. My original topic was "Open strokes are rendered incorrectly" and not "Open paths are rendered with a stroke."

It's an entirely different meaning.

I'm using shape strokes, new in CS6, and not layer effects. But see my comments further down, there's more to reproducing it.

It's a bug.

Are you using a layer style stroke or stroke from the tool options bar?

Reproduce case:

Photoshop incorrectly strokes between the start/end of an open path, if that path was created as a standalone path, and PASTED into a shape.

So it's another bug, Chris :)

EDIT: It also starts adding open/close strokes on other shapes.

Apparently mixing/pasting shapes loses state about what to stroke at some point, or something.

Wait, that's odd, this didn't happen right now.

It means the reproduce case is more specific. Stay tuned.

EDIT: See below.