git merge a b when a == b but neither == o is always a successful merge?

    Given a repository setup thusly:

$ git --version git version 2.2.0.rc2

git init .

echo '0.0' > version
git add version
git commit -m "master"
for i in a b ; do
  git checkout -b $i master

  echo '0.1' > version
  git commit -a -m "leg $i"
done

git checkout -b c master echo '0.2' > version git commit -a -m "leg c"

git checkout --detach a

"git merge c" produces the expected edit conflict.

"git merge b" produces a successful merge, as both branches perform the "same" work.

For the body of content in question, this is a merge conflict. Git seems to have the hard-coded assumption otherwise. I had to change three source files to get the result I expected, and wasn't seeing any indications of parameterization.

Am I missing some means of getting the results I need?  Thanks!