reset: add an example of how to split a commit into two
It is often useful to break a commit into multiple parts that are more logical separations. This can be tricky to learn how to do without the brute-force method if re-writing code or commit messages from scratch. Add a section to the git-reset documentation which shows an example process for how to use git add -p and git commit -c HEAD@{1} to interactively break a commit apart and re-use the original commit message as a starting point when making the new commit message. Signed-off-by: Jacob Keller <jacob.keller@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jacob Keller committed
Feb 3, 2017 at 12:28 UTC
7326451bedaa67d29afe02184b166e28d9393c91
1 file changed
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Documentation/git-reset.txt
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@@ -292,6 +292,44 @@ $ git reset --keep start <3>
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<3> But you can use "reset --keep" to remove the unwanted commit after
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you switched to "branch2".
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+Split a commit into two::
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++
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+Suppose that you have created a commit, but later decide that you want to break
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+apart the changes into two logical chunks and commit each separately. You want
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+to include part of the original commit into the first commit, while including
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+the remainder in a second commit. You can use git reset to rewind the history
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+without changing the index, and then use git add -p to interactively select
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+which hunks to put into the first commit.
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++
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+------------
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+$ git reset HEAD^ <1>
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+$ git add -p <2>
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+$ git diff --cached <3>
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+$ git commit -c HEAD@{1} <4>
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+...
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+$ git add ... <5>
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+$ git diff --cached <6>
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+$ git commit ... <7>
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+------------
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++
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+<1> First, reset the history back one commit so that we remove the original
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+ commit, but leave the working tree with all the changes.
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+<2> Now, interactively select hunks to add to a new commit using git add -p.
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+ This will ask for each hunk separately and you can use simple commands like
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+ "yes, include", "no don't include" or even "edit".
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+<3> Once satisfied with the hunks, you should verify that it is what you
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+ expected by using git diff --cached to show all changes in the index.
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+<4> Next, commit the changes stored in the index. "-c" specifies to load the
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+ editor with a commit message from a previous commit so that you can re-use the
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+ original commit message. HEAD@{1} is special notation to reference what
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+ HEAD used to be prior to the reset command. See linkgit:git-reflog[1] for
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+ more details.
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+<5> Now you've created the first commit, and can repeat steps 2-4 as often as
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+ you like to break the work into any number of commits. Here we show a second
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+ step which simply adds the remaining changes.
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+<6> Then check again that the changes are what you expected to add.
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+<7> And finally commit the remaining changes.
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+
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DISCUSSION
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