Question

Say, if the file foo is committed already, having the content of

just a simple line

now a git checkout -b issue57 is done to create a branch and switch to it (say, that issue57 branch is to last 2 days for development), and a line footer added is added to the file for now, and then a git commit -a -m "add a footer to the file".

So now the file foo has the content

just a simple line
footer added

When a “hot fix” or “quick fix” is needed, I thought the command git checkout master should be used, and now the content of the file foo should be back to that just one single line. But when I do more foo, the file has both lines, why is that?

Answer 1

Works just fine for me:

$ more foo
just a simple line
$ echo "footer added" >> foo
$ git checkout -b issue57
M   foo
Switched to a new branch 'issue57'
$ git commit -a -m "add a footer to the file"
[issue57 c397054] add a footer to the file
1 file changed, 1 insertion(+)
$ more foo
just a simple line
footer added
$ git checkout master
$ more foo
just a simple line

Maybe you have committed the file before git checkout -b issue57?