contrib/subtree: fix "subtree split" skipped-merge bug
'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@realtimegenomics.com>
Reviewed-by: David A. Greene <greened@obbligato.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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 @@
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 $?
