Previously on demand mode was determined by frame offset parameter being
greater than zero. However, if the application is not pumping frames with
FrameMark macro, the frame index will never increase and the frame offset
parameter stay at zero. It is not possible to distinguish on demand traces
from normal ones in this scenario.
Fix by explicitly saving the on demand flag in trace file and employ the
previous logic to set the flag when importing older traces.
Bartosz Taudul