Git allowing me to switch branches without committing changes

Question

I am just learning Git, going through a tutorial. I am in branch seo_title and I have uncommitted changes to file mission.html. I did git checkout master expecting

Answer 1

This is the normal behavior. If you don't want the modified files on your newly checked out branch, then stash them. Like this.

# on branch dev
$ git stash
$ git checkout master

# do stuff on master

# back to dev
$ git checkout dev
$ git stash pop

Answer 2

The different behaviour you saw from the last time you tried to switch branches with local changes and now is due to different file changes.

So, let's say we have a branch called 'readme' where you have committed some changes to a file, let's say README.md.

Now, you have switched back to master. You do some work on other files (not README.md). Now you have local changes. If you try to switch back to the 'readme' branch without committing your changes, it will let you. Why? Because switching to the 'readme' branch won't override any of your local changes.

If, however you make a modification to the README.md file on the master branch, then when you try to do a

git checkout readme 

you will encounter

error: Your local changes to the following files would be overwritten by checkout: README.md
Please, commit your changes or stash them before you can switch branches.

because you have changes to README.md that would require a merge.

Answer 3

Git - the stupid content tracker. It just operates with working tree snapshots. The main requirement - you should be able to reconstruct working tree. It does update of course. But if the modified file is the same in both branches - why not to allow switch? If you done it by mistake, you could switch back reconstructing previous state, no big deal. But if the file is differ in the branches, you need merge content, that's why it insists to commit changes, otherwise it will be impossible to go back.

Answer 4

this is obvious, if you change a file which is not changed in the branch you want to checkout into, because the syntactic of checkout is to bring all the index and working directory to your new branch, you will have them appeared in your new branch. While if there r conflicts, chances r u need to merge those files, which means once after merge, if you checkout back to your old branch then it is already the merged version not your previous one, you lose it. As a result, to make sure you keep the old change it won't let you do that.

Answer 5

Git will let you checkout other branches (or tags or SHA1 hashes) as long as the commit you're changing your work-tree to does NOT clobber your local uncommitted changes.

In your case the branch master's work-tree would have had the same version of missing.html as that currently exists in the tip of your current branch you were switching from. Git does not need to touch the working copy (for missing.html at least) when changing branches here, and hence lets you keep your local modifications.

If you indeed tried to checkout a commit where there was a different version of missing.html in the work-tree (than the one committed in your current branch), git would show an error message similar to this:

$ git checkout some-other-branch
error: Your local changes to the following files would be overwritten by checkout:
        missing.html
Please, commit your changes or stash them before you can switch branches.
Aborting