improved rev_is_descendant_of_branch() function

diff --git a/git-subtree.sh b/git-subtree.sh
index 48bc570390248c0ccbeeab754e442f9f305568a6..66ce251eaafc41e607ee0dec37e8b172bf8f6c93 100755 (executable)
--- a/git-subtree.sh
+++ b/git-subtree.sh
@@ -166,9 +166,9 @@ rev_is_descendant_of_branch()
        newrev="$1"
        branch="$2"
        branch_hash=$(git rev-parse $branch)
-       match=$(git rev-list $newrev | grep $branch_hash)
+       match=$(git rev-list -1 $branch_hash ^$newrev)
 
-       if [ -n "$match" ]; then
+       if [ -z "$match" ]; then
                return 0
        else
                return 1