Re: [PATCH 4/6] am --abort: revert changes introduced by failed 3way merge
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Jun 8, 2015, 20:09 UTC
- Message-ID
- <xmqqd2169d3q.fsf@gitster.dls.corp.google.com>
- In-Reply-To
- <1433591172-27077-5-git-send-email-pyokagan@gmail.com>
Paul Tan <pyokagan@gmail.com> writes:
Show 36 quoted lines
> 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 $orig_head > git reset ORIG_HEAD
What would the last "reset" do when ORIG_HEAD is invalid? In other words, does it make sense to worry about the case where ORIG_HEAD does not exist? At which point in the flow does it get written using what information?
Show 41 quoted lines
> fi > rm -fr "$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