partly cherry-picking a commit with git

Question

i'm working on 2 different branches release and development.
now i noticed i still need to integrate some changes that were committed to the release branch back into the development branch.
the problem is i don't need all of the commit. only some hunks in certain files. so a simple

git cherry-pick bc66559

does not do the trick.
when i do a

git show bc66559

i can see the diff but don't really know a good way of applying that partially to my current working tree.
any suggestions would be very welcome!

Answer 1

The core thing you're going to want here is git add -p (-p is a synonym for --patch). This provides an interactive way to check in content, letting you decide whether each hunk should go in, and even letting you manually edit the patch if necessary.

To use it in combination with cherry-pick:

git cherry-pick -n <commit>   # get your patch, but don't commit (-n = --no-commit)
git add -p                    # make all your choices
git commit                    # make the commit!

(Thanks to Tim Henigan for reminding me that git-cherry-pick has a --no-commit option!)

You can of course provide specific paths to add -p if necessary. If you're starting with a patch you could replace the cherry-pick with apply.

Answer 2

Assuming the changes you want are at the head of the branch you want the changes from, use git checkout

for a single file :

git checkout branch_that_has_the_changes_you_want path/to/file.rb

for multiple files just daisy chain :

git checkout branch_that_has_the_changes_you_want path/to/file.rb path/to/other_file.rb