'git subtree split' can incorrectly skip a merge even when both parents act on the subtree, provided the merge results in a tree identical to one of the parents. Fix by copying the merge if at least one parent is non-identical, and the non-identical parent is not an ancestor of the identical parent. Also, add a test case which checks that a descendant remains a descendent on the subtree in this case. Signed-off-by: Dave Ware <davidw@xxxxxxxxxxxxxxxxxxxx> --- contrib/subtree/git-subtree.sh | 12 ++++++-- contrib/subtree/t/t7900-subtree.sh | 60 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 70 insertions(+), 2 deletions(-) diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh index edf36f8..5c83727 100755 --- a/contrib/subtree/git-subtree.sh +++ b/contrib/subtree/git-subtree.sh @@ -479,8 +479,16 @@ copy_or_skip() p="$p -p $parent" fi done - - if [ -n "$identical" ]; then + + copycommit= + if [ -n "$identical" ] && [ -n "$nonidentical" ]; then + extras=$(git rev-list --count $identical..$nonidentical) + if [ "$extras" -ne 0 ]; then + # we need to preserve history along the other branch + copycommit=1 + fi + fi + if [ -n "$identical" ] && [ -z "$copycommit" ]; then echo $identical else copy_commit $rev $tree "$p" || exit $? diff --git a/contrib/subtree/t/t7900-subtree.sh b/contrib/subtree/t/t7900-subtree.sh index 751aee3..c5089c3 100755 --- a/contrib/subtree/t/t7900-subtree.sh +++ b/contrib/subtree/t/t7900-subtree.sh @@ -1014,4 +1014,64 @@ test_expect_success 'push split to subproj' ' ) ' +# +# This test covers 2 cases in subtree split copy_or_skip code +# 1) Merges where one parent is a superset of the changes of the other +# parent regarding changes to the subtree, in this case the merge +# commit should be copied +# 2) Merges where only one parent operate on the subtree, and the merge +# commit should be skipped +# +# (1) is checked by ensuring subtree_tip is a descendent of subtree_branch +# (2) should have a check added (not_a_subtree_change shouldn't be present +# on the produced subtree) +# +# Other related cases which are not tested (or currently handled correctly) +# - Case (1) where there are more than 2 parents, it will sometimes correctly copy +# the merge, and sometimes not +# - Merge commit where both parents have same tree as the merge, currently +# will always be skipped, even if they reached that state via different +# set of commits. +# + +next_test +test_expect_success 'subtree descendant check' ' + subtree_test_create_repo "$subtree_test_count" && + test_create_commit "$subtree_test_count" folder_subtree/a && + ( + cd "$subtree_test_count" && + git branch branch + ) && + test_create_commit "$subtree_test_count" folder_subtree/0 && + test_create_commit "$subtree_test_count" folder_subtree/b && + cherry=$(cd "$subtree_test_count"; git rev-parse HEAD) && + ( + cd "$subtree_test_count" && + git checkout branch + ) && + test_create_commit "$subtree_test_count" commit_on_branch && + ( + cd "$subtree_test_count" && + git cherry-pick $cherry && + git checkout master && + git merge -m "merge should be kept on subtree" branch && + git branch no_subtree_work_branch + ) && + test_create_commit "$subtree_test_count" folder_subtree/d && + ( + cd "$subtree_test_count" && + git checkout no_subtree_work_branch + ) && + test_create_commit "$subtree_test_count" not_a_subtree_change && + ( + cd "$subtree_test_count" && + git checkout master + git merge -m "merge should be skipped on subtree" no_subtree_work_branch + + git subtree split --prefix folder_subtree/ --branch subtree_tip master && + git subtree split --prefix folder_subtree/ --branch subtree_branch branch + check_equal $(git rev-list --count subtree_tip..subtree_branch) 0 + ) +' + test_done -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html