merging branch to HEAD when branch contains partly trunk changes already

[HK]

Suppose the following situation.

 +-1.25.2 .. -- 1.25.2.2 -- 1.25.2.5
 |               ^
 |               |merge in
1.25 -- ... -- 1.27 -- ... -- 1.31

At 1.25 I created a branch.
Later I merged the changes between 1.25 and 1.27
into the branch at 1.25.2.2 to have minor updates
of the main trunk also in the branch.

Now I want to merge the branch back into the trunk.

I tried a straighforward merge of the
tip of the branch with the tip of the trunk
and get only minor conflicts.

Am I just lucky with that? Normally I would
expect all the changes between 1.25 and 1.27
to conflict, because they are in the branch but
also already in the trunk. Or does CVS silently
ignore changes which would not change anything
in this case? (I am making sense?)

  Harald.