net rpc trustdom add was broken. The default 10second timeout can be too short to create an account on a Samba DC (calling out to a script), error message reporting was poor, and more importantly the new marshalling code for user_info23 was broken (maps onto a user_info21 but doesn't clear the user_info23 struct before marshalling, leaving an uninitialized size field - give "alloc failure").
Created attachment 3375 [details]
Fixes the bug here. Please test.
Closing out bug report.
Please re-open if it is still an issue.