First and last keyframes should not change values when trimming
Submitted by Jeff F.T.
Assigned to Jeff F.T.
Set up a clip on the timeline with a keyframe curve that fades down to zero, so basically with four keyframes: 0, 100, 100, 0.
Drag one of the trimming handles: if you drag the beginning's trim handle to the right (or if you drag the end's trim handle to the left), you will see one of the zeroes become something else inbetween zero and 100.
Instead, it should stay "clamped" to whatever value it had, since the first and last keyframes are kinda special.
Imported from https://bugzilla.gnome.org/show_bug.cgi?id=709242