Hi, I think it would be better if git can warn use if we switch to another branch without committing the modification. Git will warn if the modification is based on a commit different from where the checkout happened. For example, say I am now on branch 'master' and all files *clean*. Now if I do: $ git checkout -b issue and make some changes to a file: $ echo "modification on branch issue" >> lala.txt and then switch back to branch 'master': $ git checkout master and git can see the changes: $ git status On branch master Changes not staged for commit: (use "git add <file>..." to update what will be committed) (use "git checkout -- <file>..." to discard changes in working directory) modified: lala.txt no changes added to commit (use "git add" and/or "git commit -a") Now, if I do "git checkout -- lala.txt", then I will lose that change on branch 'issue' too!!! If, on branch 'issue', the changes to 'lala.txt' are based on a commit different from where the checkout happened, i.e. on branch 'master' | | <-- git checkout -b issue \ \ <-- modification to git happened on a commit different from where the checkout happened then git would warn us something like this: error: Your local changes to the following files would be overwritten by checkout: lala.txt Please, commit your changes or stash them before you can switch branches. Aborting So, I think it is better to add some similar warinings if the modification happened on a commit the *same* as where the checkout happened, i.e. on branch 'master' | | <-- git checkout -b issue <-- modification to git happened on a commit different from where the checkout happened I already lost some of my work by this ... (p.s please add me to the Cc because I am not in this list) --- Yubin