Sweep1 untrimmed miters option breaks history in certain cases

In the attached, a sweep1 with untrimmed miters (the only chance for success with this configuration) breaks the history. This seems to be a special case with polyline input rails, other rail types seem to work correctly.

Note these objects do have history, if you do a SelObjectsWithHistory. You also get a “History failed to update 1 object” message if you modify the rail for example.

Sweep-HistoryBreak.3dm (116.5 KB)

Hi Mitch - I see that, thanks.