ottava in voice 2 is attached to whole measure rest in voice 1

test_of_ottava in voice 2.mscz
In the attached score, I entered notes in voice 2 (or voice 4) and then an ottava on the first note of each measure. The ottava attaches to the whole measure rest in voice 1. In one case, I entered the notes in voice 1, attached the ottava, and exchanged voices 1 and 2. The ottava attached itself to the new voice 1. In measure 8, I moved the start of the ottava one step back by Shift <-- and it moved to the previous measure. In the last measure I corrected the start by Ctrl <--. I then deleted the measures which followed so that the remaining measures were stretched and the corrected start was no longer correct. My interest is when the ottava is attached to small notes in a cue, but the bug occurs even when the notes are normal size.
GIT commit: f51dc11