Your answer there is most helpful, as well as the Blog entry that Poppet quoted (http://blog.secondlife.com/2006/08/14/when-an-exploit-isnt-an-exploit/#more-207):
The short of it: never change permissions on an object in your inventory. This flags the object for resave or “permissions slam” on rez, causing the object to still have the same permissions it had when last taken into inventory — even after the object is sold or transferred to someone else. This is a long-standing issue that I’ve been told “isn’t trivial to fix”. I’ll keep on the developers about it, though! For now if you absolutely have to modify next-owner permissions in inventory, rez the object and take it again to save the changes.
But the information above isn't correct. Rezzing and taking the object again after modifying the perms in one's inventory will cause another "bug". Here are the possible two cases:
1.) I create a complex linkset, set the permissions to +M -C +T and pick it up. In my inventory, the next owner permissions look like -M -C -T. That's right, no permissions at all; it doesn't happen with a single prim, but complex linksets of 20+ prims. If I sell it like this, the customer will see (no copy) (no modify) (no trade) in his inventory - after rezzing the object, the permissions are fine again, but who would think of that? Many people purchase something as a gift and then complain because they can't trade it. So I did the following instead:
2.) I build something, pick it up and then set the permissions in my inventory only. The perms look just fine to the next owner: +M -C +T. It can be traded as a gift now, but as soon as it is rezzed the perms revert to whatever was automatically applied when I built it, so it will likely lose the trade permission. That's the bug that haunted me for months now.
What complicates things is that avatar attachments don't behave like they were rezzed when they're worn. Rezzing something on one's body won't change the permissions, it will still have the "inventory permissions". With an attachment, the 2 cases above look like this:
1.) I build a complex prim skirt, set the permissions to +M +C -T and pick it up. It will likely lose the modify permission (as I said, it only happens with larger linksets). The next owner drags it onto her avatar and finds out she can't modify it. Rezzing on the floor / picking it up would repair the permissions here too of course, but no one knows that.
2.) I don't bother to look at the permissions of the skirt, just pick it up and set them in my inventory. Everything's fine, the modify permission stays after the customer rezzed the skirt on her body. But one day she has the idea to link something like a furry tail to the skirt, since both items are worn on the same attachment spot. She rezzes the skirt on the ground - modify permission gone. If the skirt had no copy permission, it'd be ruined now.
Brent wrote, if I have to change the permissions in my inventory, I should rez it afterwards and pick it up again. If I do that, I'll end up with wrong inventory permissions again, just as in case 1. the only workaround is to set the permissions twice, once while the object is rezzed and then again in the inventory. I know that now, but other crafters out there will likely run into the same problem. Could it be changed in the knowledge base (http://secondlife.com/knowledgebase/article.php?id=171)?
