Added a --onto option, but it's so complicated I can't tell if it works.
diff --git a/git-subtree.sh b/git-subtree.sh
index af1d332..7e1707a 100755
--- a/git-subtree.sh
+++ b/git-subtree.sh
@@ -13,7 +13,7 @@
h,help show the help
q quiet
v verbose
-onto= existing subtree revision to connect, if any
+onto= existing subtree revision to search for parent
rejoin merge the new branch back into HEAD
"
eval $(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)
@@ -172,6 +172,16 @@
debug "Splitting $dir..."
cache_setup || exit $?
+ if [ -n "$onto" ]; then
+ echo "Reading history for $onto..."
+ git rev-list $onto |
+ while read rev; do
+ # the 'onto' history is already just the subdir, so
+ # any parent we find there can be used verbatim
+ cache_set $rev $rev
+ done
+ fi
+
unrevs="$(find_existing_splits "$dir" "$revs")"
git rev-list --reverse --parents $revs $unrevs -- "$dir" |
