Comment by gknoy

I've never noticed that before, but it's possible that you both had added functions in different places:

    foo() ... ; original

    bar() ...  ; added by alice
    foo() ...

    foo() ...
    bar() ...  ; added by bob

I haven't tried it, but I could imagine that being seen as separate text additions, and ending up with duplicates if git thinks it needs to merge them:

    bar() ... ; alice
    foo() ... ; original
    bar() ... ; bob

You mentioned using `git pull`, which will actually merge things if it thinks it's necessary -- which can lead to tree differences. In practice, I've found it helpful to NEVER USE `git pull`. Rather, I advise using:

    git checkout master
    git fetch origin
    git merge origin/master --ff-only

This will ensure that git only does "fast-forward" merges, and does not end up accidentally merging things - and keeps 'origin' as the system-of-record for what's been merged.