From: Yuki Kokubun <orga.chem.job@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: git@vger.kernel.org
Subject: Re: [PATCH] filter-branch: consider refs can refer to an object other than commit or tag
Date: Wed, 21 Mar 2018 20:00:00 +0000 [thread overview]
Message-ID: <5ab2b606.86f5620a.c0c10.41b3@mx.google.com> (raw)
In-Reply-To: <xmqqwoy5pcno.fsf@gitster-ct.c.googlers.com>
> Yuki Kokubun <orga.chem.job@gmail.com> writes:
>
> > "git filter-branch -- --all" can be confused when refs that refer to objects
> > other than commits or tags exists.
> > Because "git rev-parse --all" that is internally used can return refs that
> > refer to an object other than commit or tag. But it is not considered in the
> > phase of updating refs.
>
> Could you describe what the consequence of that is? We have a ref
> that points directly at a blob object, or a ref that points at a tag
> object that points at a blob object. The current code leaves both of
> these refs in "$tempdir/heads". Then...?
Sorry, this is my wrong.
I wrongly thought only refs/replace can point at a blob or tree object.
>
> ... goes and looks ...
>
> There is a loop that looks like this:
>
> while read ref
> do
> sha1=$(git rev-parse "$ref^0")
> ...
> done <"$tempdir/heads"
>
> which would break on anything but a commit-ish.
>
> > # The refs should be updated if their heads were rewritten
> > git rev-parse --no-flags --revs-only --symbolic-full-name \
> > - --default HEAD "$@" > "$tempdir"/raw-heads || exit
> > + --default HEAD "$@" > "$tempdir"/raw-objects || exit
> > +# refs/replace can refer to an object other than commit or tag
>
> Mention of replace refs in the proposed log message gives an easy to
> understand example and is a good idea, but this in code comment does
> not have to single out the replace refs. A tag can also point at an
> object with any type, e.g. "git tag v2.6.11-tree v2.6.11^{tree}"
> would make "refs/tags/v2.6.11-tree" point at the tree at the top
> level of the tree-ish "v2.6.11". It probably is OK to drop this
> comment altogether.
OK, I'm gonna drop the incorrect comment.
>
> > +while read ref
> > +do
> > + type=$(git cat-file -t "$ref")
> > + if test $type = commit || test $type = tag
> > + then
> > + echo "$ref"
> > + fi
> > +done >"$tempdir"/raw-heads <"$tempdir"/raw-objects
> > sed -e '/^^/d' "$tempdir"/raw-heads >"$tempdir"/heads
>
> So... is the idea to limit the set of refs to be rewritten to those
> that point at commits and tags? As I already alluded to, I do not
> think you want to accept a ref that points at any tag object---only
> the ones that point at a tag that points at a commit-ish, so that
> the code will not barf when doing "$ref^0".
>
> So perhaps
>
> git rev-parse --no-flags ... >"$tempdir/raw-heads" || exit
>
> while read ref
> do
> case "$ref" in ^?*) continue ;; esac
> if git rev-parse --verify "$ref^0" 2>/dev/null
> then
> echo "$ref"
> fi
> done >"$tempdir/heads" <"$tempdir/raw-heads"
>
> or something? Note that you do not need the "sed" as the loop
> already excludes the negative revs.
I feel using "git rev-parse --verify" is a good way as you said.
I'm gonna modify the patch to use it.
>
> > test -s "$tempdir"/heads ||
> > diff --git a/t/t7003-filter-branch.sh b/t/t7003-filter-branch.sh
> > index 7cb60799b..efeaf5887 100755
> > --- a/t/t7003-filter-branch.sh
> > +++ b/t/t7003-filter-branch.sh
> > @@ -470,4 +470,17 @@ test_expect_success 'tree-filter deals with object name vs pathname ambiguity' '
> > git show HEAD:$ambiguous
> > '
> >
> > +test_expect_success 'rewrite repository including refs/replace that point to non commit object' '
> > + test_when_finished "git reset --hard original" &&
> > + tree=$(git rev-parse HEAD^{tree}) &&
> > + test_when_finished "git replace -d $tree" &&
> > + echo A >new &&
> > + git add new &&
> > + new_tree=$(git write-tree) &&
> > + git replace $tree $new_tree &&
>
> Perhaps something like this here:
>
> git tag -a "tag to a tree" treetag $new_tree &&
>
> can tell su how well it works with a tag that points at a tree?
Sounds good. I'm gonna add such tags to the test case.
>
> > + git reset --hard HEAD &&
> > + git filter-branch -f -- --all >filter-output 2>&1 &&
> > + ! fgrep fatal filter-output
> > +'
> > +
> > test_done
next prev parent reply other threads:[~2018-03-21 19:44 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-21 10:35 [PATCH] filter-branch: consider refs/replace can refer to an object other than commit Yuki Kokubun
2018-03-21 15:31 ` [PATCH] filter-branch: consider refs can refer to an object other than commit or tag Yuki Kokubun
2018-03-21 17:21 ` Junio C Hamano
2018-03-21 20:00 ` Yuki Kokubun [this message]
2018-03-21 20:00 ` Junio C Hamano
2018-03-22 14:26 ` Yuki Kokubun
2018-03-22 17:01 ` Junio C Hamano
2018-03-23 2:15 ` Yuki Kokubun
2018-03-23 5:09 ` [PATCH v2] filter-branch: fix errors caused by refs that cannot be used with ^0 Yuki Kokubun
2018-03-23 20:20 ` Junio C Hamano
2018-03-24 19:41 ` [PATCH v3] filter-branch: fix errors caused by refs that point at non-committish Yuki Kokubun
2018-03-25 16:25 ` Junio C Hamano
2018-03-25 16:39 ` Yuki Kokubun
2018-03-25 20:24 ` Junio C Hamano
2018-03-25 16:54 ` [PATCH v4] " Yuki Kokubun
2018-03-25 16:45 ` Yuki Kokubun
2018-04-08 23:10 ` Junio C Hamano
2018-03-25 17:01 ` [PATCH v5] " Yuki Kokubun
2018-03-25 17:13 ` [PATCH v4] " Junio C Hamano
2018-03-24 19:29 ` [PATCH] filter-branch: consider refs can refer to an object other than commit or tag Yuki Kokubun
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