Merging directories

[pinkfloydhomer]

Suppose I have two directories, A and B, that are checked out versions
of _different_ CVS projects.  These two different projects happen to
come from the same ancestor, but are now unrelated projects, CVS-wise.

Can I merge the changes in A into B (recursively) using diff and patch
somehow?

That is, directories that exist in A but not in B will be created in B.
Files that exist in A but not in B will be copied.
Files that exist in A and B will be updated in B to contain the
differences in A, if no conflicts.
Conflicts are inserted into files as when patching.

I guess I am asking: Can I make a patch for a whole directory,
recursively? How do I make it? How do I apply it?

/David