Deleting curve from Pose Asset sets mesh back to default pose

REGRESSION: Yes. Issue occurs in 4.15, but does not occur in 4.14.3

When the user deletes a curve from a pose asset, the mesh will revert to default pose, even if it was showing a pose. The Pose's weight will not be updated.

1. Open QAGame in editor.
2. Open the Pose Asset Test_Pose.
3. In the Pose List, double-click Shocked.
4. In the Curve List, right-click Terror_Full and select Delete.

RESULT

The curve is deleted, and though Shocked is still set to 1, the mesh goes into A-pose.