Combine a tree into its containing tree.
bzr join TREE
This command requires the target tree to be in a rich-root format.
The TREE argument should be an independent tree, inside another tree, but not part of it. (Such trees can be produced by “bzr split”, but also by running “bzr branch” with the target inside a tree.)
The result is a combined tree, with the subtree no longer an independant part. This is marked as a merge of the subtree into the containing tree, and all history is preserved.