After the patch with clipping masks/paths was applied, I'm figuring out how to solve an issue with tranforms on masks. The problem is:

*If any object to which a mask is applied is transformed already, mask is placed on wrong place

*If masked object is moved, unmasking places mask object in wrong place

 

First solution that comes in mind - for first issue take a transformation of masked item, invert it and apply to a mask item (the ones which is moved to defs), for second issue - take transform of masked item and apply it to masked item which is moved back from defs.

 

But that does not solve same issue for multiple items which are masked/unmasked. So, quickest solution I see - if mask is beeing applied to multiple items, make an ordinary group and apply mask to it. That still does not solve an issue with unmasking multiple items whick mask was set manually or externally - for those we can just say, that unmask transform is calculated by the last item which mask is removed.

 

So, if there are no objections, I will implement that behavior.

 

Andrius