am -3: support 3way merge on unborn branch

While on an unborn branch, git am -3 will fail to do a threeway merge as
it references HEAD as "our tree", but HEAD does not point to a valid
tree.

Fix this by using an empty tree as "our tree" when we are on an unborn
branch.

Signed-off-by: Paul Tan <pyokagan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Paul Tan 2015-06-06 19:46:08 +08:00 committed by Junio C Hamano
parent 88d5072466
commit 2c970c9ec3
2 changed files with 11 additions and 1 deletions

View File

@ -178,7 +178,8 @@ It does not apply to blobs recorded in its index.")"
then
GIT_MERGE_VERBOSITY=0 && export GIT_MERGE_VERBOSITY
fi
git-merge-recursive $orig_tree -- HEAD $his_tree || {
our_tree=$(git rev-parse --verify -q HEAD || echo $empty_tree)
git-merge-recursive $orig_tree -- $our_tree $his_tree || {
git rerere $allow_rerere_autoupdate
die "$(gettext "Failed to merge in the changes.")"
}

View File

@ -83,4 +83,13 @@ test_expect_success 'am --abort will keep the local commits intact' '
test_cmp expect actual
'
test_expect_success 'am -3 stops on conflict on unborn branch' '
git checkout -f --orphan orphan &&
git reset &&
rm -f otherfile-4 &&
test_must_fail git am -3 0003-*.patch &&
test 2 -eq $(git ls-files -u | wc -l) &&
test 4 = "$(cat otherfile-4)"
'
test_done