Why do these rests appear with slash voice?

pianoleo · November 7, 2021, 1:04pm

See Unasked for flipping of notes - #23 by pianoleo for instance.

Specifically this bit:

One voice is always considered to be the primary voice. It will continue padding with rests for the entire length of the flow. When you introduce a second voice but stop adding notes to the first voice, the first voice will end of the last bar in which it contains notes.

By way of an example:
The blue voice is Up-stem voice 1
The red voice is Down-stem voice 1

Up-stem voice 1 (blue) is the primary voice until Down-stem voice 1 (red) appears - and because at this point there’s only one voice visible at any one time, the nominal stem direction is irrelevant.
When I copy and paste three Up-stem Voice 1 notes to the middle of bar 4, Dorico no longer truncates Up-stem voice 1 at the end of bar 2; it extends the voice all the way through to the beginning of bar 5 (and beyond, given there are no more notes in Down-stem Voice 1).