Git checkout no longer warns of unchanged files

I开发者_C百科f I have some changes in BranchA and then checkout BranchB those files are auto merged into BranchA.

I used to get a warning that forced me to either commit or stash the changes: something like: my_file.rb would be overwritten by merge. Cannot merge.

At some point this stopped happening. Any thoughts? Here's my .getconfig

[user]
        name = <my name>
        email = <my email>
[core]
        repositoryformatversion = 0
        filemode = true
        bare = false
        logallrefupdates = true
        ignorecase = true
[color]
        ui = always
        interactive = always
        diff = auto
        branch = auto
        status = auto
[color "diff"]
        new = cyan
        old = magenta
        frag = yellow
        meta = green
        commit = normal
[alias]
        co = checkout
        ci = commit
        st = status
        br = branch
        hist = log --pretty=format:\"%h %ad | %s%d [%an]\" --graph --date=short
        type = cat-file -t
        dump = cat-file -p

It's only changes that you haven't commited yet that git complains about.

Update:

While answering a similar question, I realized that I had answered this same question elsewhere as well and while searching, also came across this answer that I had made sometime earlier. Below is the link to that answer, which I believe is to be the right one:

Git branches behaving strangely

Old answer:

Unless you are using git checkout -m or -f it should still be saying that.

What does git status tell you?