branch efficiency

I am wondering if the "cheap copies" are used when merging changes from a
modified file on a branch to an unmodified file on the trunk (or vice
versa). Since my question might not be clear consider the following
scenario:
(I acknowledge that this is an extreme example)
A branch is created.
Changes are made to a relatively small number of files (lets say 1 file) and
committed to the branch.
Time goes by with 100's of files changed/added on the trunk.
Meanwhile the branch has been untouched.
The branch creator wants to continue using the branch, but would like to
merge all the changes from the trunk into the branch.

Does this merge use "cheap copies" to create the new revisions of the files
on the branch, or does branching prevent the usage of hardlinks?
Received on Thu Nov 8 00:43:18 2007