How to split git commit into two parts based on the same parent?

Question

I'm on foo branch, with parent A:

---A---foo

I want to split the changes from A to foo into two branches, as based on A. I believe that I can do half the work as follows:

git checkout -b halfFoo
git reset HEAD~
    # Only choose half the stuff.
git add -i
git commit

This gives me:

---A---foo
    \
     \-halfFoo

I know how to do this (git checkout -b otherHalfFoo; git commit -a):

---A---foo
    \
     \-halfFoo
      \
       \-otherHalfFoo

But I would like to get this:

---A---foo
   |\
   | \-halfFoo
    \
     \-otherHalfFoo'

How can I do this without having to go through git add -i '(and selecting a negative result for what was chosen for HalfFoo)?

Answer 1

First, rewind the previous commit, leaving after that change. Then open and apply some changes. Open the source branch again and apply the rest of the changes.

git branch original_tip_with_foo  # if you want a reference to the foo commit
git reset HEAD~
git stash
git branch branch_2  # we'll get there in a moment ...
git checkout -b branch_1
git stash pop
git add -p
# ... add your first set of changes, for the first branch ...
git commit -m'first set of changes'
git stash
git checkout branch_2
git stash pop
git add -p
# ... add your second set of changes ...
git commit -m'second set of changes'

Answer 2

:

git checkout -b branch1 foo
git rebase -i A
git checkout -b branch2 foo
git rebase -i A

, , , , , "e" "pick".

Answer 3

, , A, otherHalfFoo. reset - Foo (, HEAD ~ 1).

Answer 4

checkout -i , , . git revert , , .

foo A:

---A---foo

:

git co -b halfFoo foo~
git checkout -i foo
git commit

:

---A---foo
    \
     \-halfFoo

, foo , halfFoo, git revert:

git co -b otherHalfFooWithHistory foo
git revert halfFoo

---A---foo
    \     \-otherHalfFooWithHistory
     \-halfFoo

Which is conceptually what you want for otherHalfFoo, but has a story in which all foo exists, and then some of them were deleted. You can optionally clean it with merge --squash:

git co -b otherHalfFoo foo~
git merge --squash otherHalfFooWithHistory
git branch -D otherHalfFooWithHistory

---A---foo
   |\
   | \-halfFoo
    \
     \-otherHalfFoo