Re: [PATCH v2] reset: add an example of how to split a commit into two

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 3, 2017, 20:46 UTC
Message-ID: <xmqqzii3dmub.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <20170203202833.17666-1-jacob.e.keller@intel.com>

Jacob Keller <jacob.e.keller@intel.com> writes:

> +Split a commit into two::

Let's say "...into two (or more)" to match what appears in "SPLITTING COMMITS" section of "rebase -i" documentation. Yours is written as a sequence of more concrete steps than the existing one over there, so it may also make sense to add reference to bring readers of "git rebase --help" to this section.

> ++
> +Suppose that you have created a commit, but later decide that you want to break
> +apart the changes into two logical chunks and commit each separately. You want

"two (or more)" again. In <5> you already hint that the user can repeat 2-4 number of times.

Show 34 quoted lines

> +to include part of the original commit into the first commit, while including
> +the remainder in a second commit. You can use git reset to rewind the history
> +without changing the index, and then use git add -p to interactively select
> +which hunks to put into the first commit.
> ++
> +------------
> +$ git reset HEAD^                           <1>
> +$ git add -p                                <2>
> +$ git diff --cached                         <3>
> +$ git commit -c HEAD@{1}                    <4>
> +...
> +$ git add ...                               <5>
> +$ git diff --cached                         <6>
> +$ git commit ...                            <7>
> +------------
> ++
> +<1> First, reset the history back one commit so that we remove the original
> +    commit, but leave the working tree with all the changes.
> +<2> Now, interactively select hunks to add to a new commit using git add -p.
> +    This will ask for each hunk separately and you can use simple commands like
> +    "yes, include", "no don't include" or even "edit".
> +<3> Once satisfied with the hunks, you should verify that it is what you
> +    expected by using git diff --cached to show all changes in the index.
> +<4> Next, commit the changes stored in the index. "-c" specifies to load the
> +    editor with a commit message from a previous commit so that you can re-use the
> +    original commit message. HEAD@{1} is special notation to reference what
> +    HEAD used to be prior to the reset command. See linkgit:git-reflog[1] for
> +    more details.
> +<5> Now you've created the first commit, and can repeat steps 2-4 as often as
> +    you like to break the work into any number of commits. Here we show a second
> +    step which simply adds the remaining changes.
> +<6> Then check again that the changes are what you expected to add.
> +<7> And finally commit the remaining changes.
> +