"git checkout" obliterates not-yet-ignored files

Hi,

the problem: suppose I decide that a local file should no longer be
controlled by git. Thus I add it to .gitignore and then "git rm
--cached" it. So far so good.

However, if I subsequently modify that file and then go back to a commit
that still contains it, my local changes will be obliterated.

IMHO that's a bug – .gitignore should only be used for (not) adding
non-version-controlled files. It does not tell git to ignore changes (in
files that *are* under version control), and thus it should not allow
any git command to simply overwrite a file.

-- 
-- Matthias Urlichs