From: Junio C Hamano <gitster@pobox•com>
To: Paul Tan <pyokagan@gmail•com>
Cc: git@vger•kernel.org, Stefan Beller <sbeller@google•com>,
Johannes Schindelin <johannes.schindelin@gmx•de>
Subject: Re: [PATCH 4/6] am --abort: revert changes introduced by failed 3way merge
Date: Mon, 08 Jun 2015 13:09:13 -0700 [thread overview]
Message-ID: <xmqqd2169d3q.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <1433591172-27077-5-git-send-email-pyokagan@gmail.com> (Paul Tan's message of "Sat, 6 Jun 2015 19:46:10 +0800")
Paul Tan <pyokagan@gmail•com> writes:
> Even when a merge conflict occurs with am --3way, the index will be
> modified with the results of any successfully merged files. These
> changes to the index will not be reverted with a
> "git read-tree --reset -u HEAD ORIG_HEAD", as git read-tree will not be
> aware of how the current index differs from HEAD or ORIG_HEAD.
>
> To fix this, we first reset any conflicting entries in the index. The
> resulting index will contain the results of successfully merged files
> introduced by the failed merge. We write this index to a tree, and then
> use git read-tree to fast-forward this "index tree" back to ORIG_HEAD,
> thus undoing all the changes from the failed merge.
>
> When we are on an unborn branch, HEAD and ORIG_HEAD will not point to
> valid trees. In this case, use an empty tree.
>
> Signed-off-by: Paul Tan <pyokagan@gmail•com>
> ---
> git-am.sh | 6 +++++-
> t/t4151-am-abort.sh | 23 +++++++++++++++++++++++
> 2 files changed, 28 insertions(+), 1 deletion(-)
>
> diff --git a/git-am.sh b/git-am.sh
> index 67f4f25..e4fe3ed 100755
> --- a/git-am.sh
> +++ b/git-am.sh
> @@ -519,7 +519,11 @@ then
> git rerere clear
> if safe_to_abort
> then
> - git read-tree --reset -u HEAD ORIG_HEAD
> + head_tree=$(git rev-parse --verify -q HEAD || echo $empty_tree) &&
> + git read-tree --reset -u $head_tree $head_tree &&
> + index_tree=$(git write-tree) &&
> + orig_head=$(git rev-parse --verify -q ORIG_HEAD || echo $empty_tree) &&
> + git read-tree -m -u $index_tree $orig_head
> git reset ORIG_HEAD
What would the last "reset" do when ORIG_HEAD is invalid? In other
words, does it make sense to worry about the case where ORIG_HEAD
does not exist? At which point in the flow does it get written using
what information?
> fi
> rm -fr "$dotest"
> diff --git a/t/t4151-am-abort.sh b/t/t4151-am-abort.sh
> index ea4a49e..2366042 100755
> --- a/t/t4151-am-abort.sh
> +++ b/t/t4151-am-abort.sh
> @@ -70,6 +70,17 @@ test_expect_success 'am -3 --skip removes otherfile-4' '
> test 4 = "$(cat otherfile-4)" &&
> git am --skip &&
> test_cmp_rev initial HEAD &&
> + test -z "$(git ls-files -u)" &&
> + test_path_is_missing otherfile-4
> +'
> +
> +test_expect_success 'am -3 --abort removes otherfile-4' '
> + git reset --hard initial &&
> + test_must_fail git am -3 0003-*.patch &&
> + test 3 -eq $(git ls-files -u | wc -l) &&
> + test 4 = "$(cat otherfile-4)" &&
> + git am --abort &&
> + test_cmp_rev initial HEAD &&
> test -z $(git ls-files -u) &&
> test_path_is_missing otherfile-4
> '
> @@ -102,4 +113,16 @@ test_expect_success 'am -3 --skip clears index on unborn branch' '
> test_path_is_missing tmpfile
> '
>
> +test_expect_success 'am -3 --abort removes otherfile-4 on unborn branch' '
> + git checkout -f --orphan orphan &&
> + git reset &&
> + rm -f otherfile-4 file-1 &&
> + test_must_fail git am -3 0003-*.patch &&
> + test 2 -eq $(git ls-files -u | wc -l) &&
> + test 4 = "$(cat otherfile-4)" &&
> + git am --abort &&
> + test -z "$(git ls-files -u)" &&
> + test_path_is_missing otherfile-4
> +'
> +
> test_done
next prev parent reply other threads:[~2015-06-08 20:09 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-06 11:46 [PATCH 0/6] am --skip/--abort: improve index/worktree cleanup Paul Tan
2015-06-06 11:46 ` [PATCH 1/6] am --skip: revert changes introduced by failed 3way merge Paul Tan
2015-06-06 11:46 ` [PATCH 2/6] am -3: support 3way merge on unborn branch Paul Tan
2015-06-06 11:46 ` [PATCH 3/6] am --skip: support skipping while " Paul Tan
2015-06-06 11:46 ` [PATCH 4/6] am --abort: revert changes introduced by failed 3way merge Paul Tan
2015-06-08 20:09 ` Junio C Hamano [this message]
2015-06-06 11:46 ` [PATCH 5/6] am --abort: support aborting to unborn branch Paul Tan
2015-06-08 20:10 ` Junio C Hamano
2015-06-09 9:18 ` Paul Tan
2015-06-06 11:46 ` [PATCH 6/6] am --abort: keep unrelated commits on " Paul Tan
2015-06-08 20:13 ` Junio C Hamano
2015-06-09 8:54 ` Paul Tan
2015-06-08 17:04 ` [PATCH 0/6] am --skip/--abort: improve index/worktree cleanup Stefan Beller
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