GtkTreeView rubberbanding does not work too well
Can be observed in
treeview1 (page 1, top-right) and set
mode of the underlying
GTK_SELECTION_MULTIPLE. Dragging from the bottom will result in the rectangle not being drawn until you reach a row (https://gitlab.gnome.org/GNOME/gtk/blob/c860a2db85072695bbc6e8b0ffbfff6873bf503c/gtk/gtktreeview.c#L5080 is hit). Dragging from a row works as expected.