Alternatively, it would be pretty easy to apply the diffs to those
   branches at the same time. I imagine that would serve the same
   purpose? (The changes are quite straightforward, and I could patch the
   three branches as well as the head without any trouble.)

this is actually dangerous.

you're only going to be applying some of "head" to these branches,
so when a later sync is done, your edits will get reverted on the
branch, and then when the branch is merged, your edits will get
reverted on the trunk.


.mrg.