Telling if two trees are different

[James Westby]

Hi all,

For the Ubuntu bzr importer I need to be able to tell, given two
trees, whether they differ in contents. I'd like to do
this in the most elegant/efficient way possible, and so I come
here to ask what that would be.

The use case is given the current tip of a branch and a 
new source package that was uploaded, does the source package
match what was in the branch?

The source package won't actually be in a branch, but it could
easily be turned in to a revision tree, which I suspect will be
needed.

My guess would be iter_changes between the two trees.

Does the best API to use depend on whether the branches are local
or remote, or anything similar to that?

Thanks,

James