Hi Nat,
I think this is intended behaviour? Makes sense to me at least, and I believe this is the way it's been working so far.
When you only have a Left clip (Clip A) in a transition and no Right clip (Clip B), we take a transparent frame and treat it as the Right clip. So in the case that you add a Fade through White to a singular clip, it will flash white in the middle of the transition, and the rest of the transition is just fading in to the Right clip. Which in this case is a transparent black frame so that you'll see Clip A -> Flash white -> Dip to black. This is logical to me and is consistent with the way that the other transitions work, but I can see how a user might want the transition to end at white. In that case we should actually add a new transition, Fade to White as opposed to Fade through White. But I don't think this transition would be useful at all the in the regular two-clip case.
Regarding the Fade transition however, I do think it initially seems a bit illogical. But here's the tooltip description of the transition: "Fade to Black, then Fade into the following clip". So really, its more like a Fade through Black then a Fade to Black. (techinically, Fade through Transparent would be a better name). So here's what happens in the singular clip case: Clip A -> Totally black at halfway point -> Fade to Clip B. As mentioned before Clip B is really a transparent frame so it pretty much just stays black from a viewer's standpoint. So again I do think this makes sense, although the tooltip was changed some time ago to 'Gradually make faint and disappear' which is far less descriptive to the user as to what is actually happening, so I'll probably change it back.
Since it's only two transitions which may be confusing to the user when applied to a singular clip, it is possible we could handle these as a special case and progress the fade twice as slowly so make it end at what was previously the middle of the transition. But at the moment I don't see it as a huge issue. Thanks for investigating, however.
