Why didn't git checkout (of a past commit) change my files?

Question

I have been building my website with a git repository for a week. So far, I have not created any branches, but I just discovered a problem on my live site which needs to be fixed. Currently, I am two commits beyond the commit that contained my site as it was when I last pushed it from my dev environment to live last week. So here is what I did:

• I did git checkout -b feature1 to create a new branch called 'feature1'
• I committed all of my current files.
• I did git log to find the hash number (afd6) of the commit that corresponds the that last live push/update.
• I did git checkout afd6

At this point I expected my work space to only contain files and revisions that I committed last week. However, My work still contains all of the files and variations from today. Am I missing a step here? I am assuming that this operation should have removed all of the tracked files that did not exist within the earlier commit, and reverted all of the files that changed today.

edit ========================

I just did git clean -f -d but nothing changed

edit =======================

git status says:

HEAD detached at afd620b nothing to commit, working directory clean

edit =========================

Actually, I made a mistake in assuming that the files did not change because I was looking at each of the file's change date. I was expecting this data to change to 'last week' after checkout. Upon closed inspection, I saw that the files actually do contain last week's code, even though the data of modification still says 'today'. Could someone verify that git checkout is considered to be a file modification by the operating system?

Answer 1

From the Git FAQ

"Git sets the current time as the timestamp on every file it modifies, but only those."

So what you are seeing is exactly those files that are returned to their prior state (based on your provided commit) have 'now' timestamps. Git doing it this say allows build tools to recognize changed files - the files that where just changed by a checkout.