title: How to get back to the latest commit after checking out a previous commit?
body: <p>I sometimes check out some previous version of the code to examine or test.  I have seen instructions on what to do if I wish to modify previous commits -- but suppose I make no changes.  After I've done e.g. <code>git checkout HEAD^</code>, how do I get back to the tip of the branch?.. <code>git log</code> no longer shows me the SHA of the latest commit.</p>