How to include full commit logs in git merge message?

Hi,

When I merge a branch, say myfix, to master,
I would like to let the merge log message contain
all commit messages I had for the branch I am 
merging.  However, the "git merge --log" only
populates one-line descriptions of the commits.

Is there any simple way to populate the full 
merge messages into the log message of the 
merge commit?

Thanks!

-Wenguang