fixup

git-branch-linearity.sh

@@ -8,7 +8,7 @@ git fetch origin $TARGET_BRANCH 2> /dev/null
 
 
 # Detection of (PR) merge commits at tip of HEAD:
-target_sha=$(git rev-parse $TARGET_BRANCH)
+target_sha=$(git rev-parse origin/${TARGET_BRANCH})
 # Get SHA of parent commit
 merge_target=$(git log --merges --oneline --parents --no-abbrev-commit HEAD^..HEAD | cut -d" " -f2)
 # If parent is the target branch, start from the commit before the merge commit