Re: Distinguishing FF vs non-FF updates in the reflog?

On Mon, Mar 22, 2021 at 5:40 PM Ævar Arnfjörð Bjarmason
[off-list ref] wrote:

On Mon, Mar 22 2021, Han-Wen Nienhuys wrote:

quoted

On Mon, Mar 22, 2021 at 4:39 PM Ævar Arnfjörð Bjarmason
[off-list ref] wrote:

quoted

We can know with !strcmp(rows[0][1], rows[1][0]) whether the latest
update is a ff or non-ff (it is). As opposed to:

    $ cut -d ' ' -f1-2 .git/logs/refs/remotes/origin/seen | head -n 2
    8b26a41f4bf7e7c0f097cb91012d08fe8ae30e7f 0f3a981cbd5be5f97e9504ab770cd88f988fe820
    0f3a981cbd5be5f97e9504ab770cd88f988fe820 fdd019edfe6bc60d0100d5751c41e4f6ad28a2ef

Where the rows[0][1] value is not the same as rows[1][0].

I'm confused.

rows[0][1] == "0f3a981cbd5be5f97e9504ab770cd88f988fe820"
rows[1][0] == "0f3a981cbd5be5f97e9504ab770cd88f988fe820"

they are the same. I don't understand your argument.

Sorry, I mean same = ff update, not the same = non-ff. So I flipped
those around in describing it.

But in any case, the point is that you can reliably tell from a log of
updates whether individual updates are ff or non-ff, as long as you:

?


$ git checkout -b non-ff origin/master
Previous HEAD position was 59f4325222 Add "test-tool dump-reftable" command.
Branch 'non-ff' set up to track remote branch 'master' from 'origin'.
Switched to a new branch 'non-ff'

$ git reset --hard HEAD^
HEAD is now at 56a57652ef Sync with Git 2.30.2 for CVE-2021-21300

$ cat .git/logs/refs/heads/non-ff
0000000000000000000000000000000000000000
13d7ab6b5d7929825b626f050b62a11241ea4945 Han-Wen Nienhuys
[off-list ref] 1616432938 +0100 branch: Created from
origin/master
13d7ab6b5d7929825b626f050b62a11241ea4945
56a57652ef8e4ca2f108a8719b8caeed5e153c95 Han-Wen Nienhuys
[off-list ref] 1616432948 +0100 reset: moving to HEAD^

How can I tell from this reflog that "moving to HEAD^" is a non-FF update?

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