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From: Chris Torek <chris.torek@gmail.com>
To: "Wang, Lei" <lei4.wang@intel.com>
Cc: "git@vger.kernel.org" <git@vger.kernel.org>
Subject: Re: [Question]: Question about "cherry-pick" internal
Date: Sun, 7 Aug 2022 09:48:27 -0700	[thread overview]
Message-ID: <CAPx1Gvd9xLdJaWiTN1MrktyEMfKmAjTx9zxOVcOnRv7r9n_ZiQ@mail.gmail.com> (raw)
In-Reply-To: <e564b1e3-0f34-dce3-400d-439a40ec4d48@intel.com>

On Wed, Aug 3, 2022 at 6:42 PM Wang, Lei <lei4.wang@intel.com> wrote:
> I heard that cherry-pick is just a kind of merge, the difference between
> it and the traditional merge is that it treats the parent commit of the
> commit you want to cherry-pick as the merge-base ...

This is indeed the case.

> [During merging:] If the [two] diff[s] modified the same
> line, then a conflict occurs.

This is also true—but it's not the whole story.

> If the above is true, but why when I cherry-picked a commit, a conflict
> occurs even the 2 diffs didn't modify the same line, they modified the
> two consecutive lines (line n and line n + 1), so what can be the
> potential reason for this?

In any merge, if the two sides modify *adjacent* lines—as is the
case here—that, too, is considered a conflict (at least Git considers
it as one; not all merge algorithms do that).

Note that if the two diffs modify the same line(s) in the *same way*—
e.g., both add the same text or delete the same text—Git will take
only *one copy* of the change, without calling it a conflict. In some
cases this may be incorrect: consider. e.g., merging the debits and
credits in a series of accounting records, where the dollar amounts
are identical, but the transactions are different.  If Alice spent $5
and Bob spent $5, the correct result is not that "$5 total was spent"
but rather $10.

Still, for the kinds of tasks *Git* is asked to merge, this is normally
the correct result, so it is the result Git produces.

Git is a tool—or rather, a set of tools—and its automated work is
never a substitute for expert evaluation.  You, the user, must do
some work here as well, to make sure that what Git did is in fact
correct for your particular situation.

Chris

  reply	other threads:[~2022-08-07 16:48 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-04  1:25 [Question]: Question about "cherry-pick" internal Wang, Lei
2022-08-07 16:48 ` Chris Torek [this message]
2022-08-08  3:27   ` Wang, Lei

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