How to apply a filter to a layer and its mask at the same time (in a single pass)?

Question

I have a layer with a mask and I'd like to modify the contents of both using a filter (e.g. Filters -> Distorts -> IWarp). The problem is that I can only edit one of them at a time and reapplying that filter is not obvious, as in case of the aforementioned filter (and likely many others) the menu item Filters -> Repeat "filter name" simply displays the configuration window for that filter and the desired changes for all of the parameters have to be reintroduced manually.

In my scenario, the mask defines the visible shape of an object, that is, in essence, just a bunch of pixels. I'd like to distort the shape and the pixels within it in the same manner, but I can't seem to find a solution to match the layer and its mask after applying the filter.

I suppose it might be impossible to achieve this directly in a single pass, but what other choices do I have in this scenario?

Answer 1

I have found a slightly destructive (some of the mask's data may be lost) way to achieve the desired effect.

One can right-click the layer (or navigate to Layer -> Mask) and select Apply layer mask, at which point the mask itself will disappear, but the layer's alpha channel will be modified accordingly. Then it is a matter of simply using the desired filter on the layer in its current state (no mask).
Then the mask can be recreated if needed, and one way to achieve that is to select Add layer mask from the context menu for the layer (or, again, the Layer -> Mask menu), and — in the dialog window — set Initialize Layer Mask to: to Transfer layer's alpha channel (as suggested by @xenoid).

It is likely that I have missed something or that there exists a more sensible solution, however this might be of use to someone, as it helped me solve the issues with my current project.