Mouse click while dragging a larva
While dragging a larva along part of its track, the user holds the left mouse button pressed. If any other mouse button is pressed in the process, the drag suspends or freezes with the active track segment still highlighted.
Releasing the left mouse button may lead to assigning the active tag to a track segment, or nothing happens in the case the mouse pointer is outside the 2D view (the drag still appears as suspended). A suspended drag eventually results in assigning a tag to a track segment, sometimes on the next drag attempt, on another larva.
In all these cases, the desirable behavior consists in cancelling the operation (no data changes).