Why are all files marked with 'merge' in TFS?

I am merging my development branch into the main branch. There is only a subset of files that I have changed in my development branch, all other files should remain unchanged. Logically, I only want to merge files which I've changed. I would not check in a file which I did not change.

But when I do the merge operation in TFS, it marks every single file in the tree with change type 'merge'. It looks like I must checkin every single file in the whole source code tree! I really do not want to do this becasue then it becomes impossible to look at the changeset and see what files I acctually changed as part of my project.

At first, I thought I could use the tfpt.exe Undo Unchanged command to undo all the 'merge' changes, but this won't undo those changes.

Anyone have any ideas on this? thanks.

Solution

There are a number of possible reasons. This is not a complete list:

You performed a namespace operation (delete, undelete, rename) on a parent folder of the files marked "merge"
You performed a namespace operation (delete, undelete, rename) that had already been performed in the target branch
You performed a sequence of namespace operations that collapsed into a no-op (eg delete + undelete, or rename a -> b -> a)
There are unresolved conflicts
You performing a discard

Note: all of these apply equally to 2005 & 2008.