jafrog's dev blog

Sometimes overuse of git cherry-pick command leads to the situation, where actual difference between two branches is no longer the one you see in git log branch1..branch2.

For example, if repo has two branches: master and experimental. Master’s history looks like this:

~/example> git checkout master
~/example> git log --oneline
4c72a0a First commit
24361e1 Initial commit

And experimental’s:

~/example> git checkout experimental
~/example> git log --oneline
31e76c6 Second experimental commit
160a97c First experimental commit
4c72a0a First commit
24361e1 Initial commit

Now let’s cherry-pick one commit to the master branch:

~/example> git checkout master
~/example> git cherry-pick 160a97c
~/example> git log --oneline
f16b462 First experimental commit
4c72a0a First commit
24361e1 Initial commit

Note that new commit has a different SHA-1 now, because cherry-pick “applies changes introduced by some existing commits”, not moves commit object itself. So now if we try to see what’s new in experimental branch compared to master brach using git log, we get this:

~/example> git log master..experimental --oneline --graph --pretty=format:'%H - %s'
* 31e76c6893f01283bae005c9af1a25a7c63b1423 - Second experimental commit
* 160a97cd0b1a32381e34ea5f72f5f39cacb77e14 - First experimental commit

There’s no difference between “First experimental commit” and “Second experimental commit” though changes presented by one of them is already in the master. But git cherry command can show that difference.

~/example> git cherry master experimental -v
- 160a97cd0b1a32381e34ea5f72f5f39cacb77e14 First experimental commit
+ 31e76c6893f01283bae005c9af1a25a7c63b1423 Second experimental commit

+ means that “upstream” (in this case master branch) lacks both commit object and it’s changes. - tells us that changes of this commit are represented by a different commit object in “upstream”.

Now a little more about command syntax:

The first argument (optional, defaults to the branch’s remote) is upstream. There’s a lot of confusion about this term, so I would recommend this question on StackOverflow. In this case upstream is simply a branch in which you want to know what commits from another branch (head) are present. The second argument “head” is also optional and defaults to current HEAD.