git merge and merge message

Hi,

I have setup several 'topic branches' for a project I am maintaining.

For several ones, I want to merge them into master.

Here is what I am trying to use:

git checkout master git merge -m "Message" topic-branch

The merge is correct but there is not merge message when I do a git log.

I have tried either with and without -m, I even tried with git merge "merge message" topic-branch but then it failed.

What is the correct way to have merge message ?

Thank you