If you set the duration of any variant or property animation to 0,
its progress will be stuck at 1 (0..1), and its "end" value set on
the target object, after start() has been called. If you change the
direction of the animation to QAbstractAnimation::Backward, you
would expect the progress to be 0 after start. Instead it's still
1; the code seems to assume that if the duration is 0, the
progress must be 1 always.
The fix is that if the duration is 0, the direction is checked to
determine whether progress should be 0 (Backward) or 1 (Forward).
Task-number: QTBUG-27969
Change-Id: Ibeca084bbbce41df1dca7b7d96c15b6b54394996
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Thierry Bastian <thierryb@filewave.com>
Reviewed-by: Magne Zachrisen <mazachri@cisco.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>