If I have software under git in several branches which code will be used when I run the code?
Will be used the master, or the one with last committed changes?
You can test it with:
mkdir test cd test vim test.R print("hi") # save with ESC, CTRL+x git add test.R git commit -m "Adding file" git branch newbranch # create new branch git checkout newbranch # switch to the new branch vim test.R # edit the file on the new branch print("bye") # save with ESC, CTRL+x cd .. cat test/test.R print("bye") R CMD BATCH test.R # Run the program with an external application cat test.Rout # observe the output > print("bye")  "bye"
So even if the changes are uncommitted the branch you were working on will be used.