$ touch foo
$ git add foo
$ git commit -m 'foo'
[master (root-commit) c123f04] foo
1 file changed, 0 insertions(+), 0 deletions(-)
create mode 100644 foo
$ git branch stuck_on_foo
$ touch bar
$ git add bar
$ git commit -m 'bar'
[master 430d59a] bar
1 file changed, 0 insertions(+), 0 deletions(-)
create mode 100644 bar
$ git checkout stuck_on_foo
Switched to branch 'stuck_on_foo'
$ gittree
* 430d59a (master) bar
* c123f04 (HEAD -> stuck_on_foo) foo
$ git merge master
Updating c123f04..430d59a