Handle it successfully if a given parent commit has no parents.

diff --git a/git-subtree.sh b/git-subtree.sh
index f2a1c6aae4561fa7d85a4a7faabe4ea8771d74b1..aeafadac95d4bb25e38d90ee58d0d9ba4f85d59f 100755 (executable)
--- a/git-subtree.sh
+++ b/git-subtree.sh
@@ -125,6 +125,16 @@ cache_set()
        echo "$newrev" >"$cachedir/$oldrev"
 }
 
+# if a commit doesn't have a parent, this might not work.  But we only want
+# to remove the parent from the rev-list, and since it doesn't exist, it won't
+# be there anyway, so do nothing in that case.
+try_remove_previous()
+{
+       if git rev-parse "$1^" >/dev/null 2>&1; then
+               echo "^$1^"
+       fi
+}
+
 find_existing_splits()
 {
        debug "Looking for prior splits..."
@@ -140,7 +150,8 @@ find_existing_splits()
                                if [ -n "$main" -a -n "$sub" ]; then
                                        debug "  Prior: $main -> $sub"
                                        cache_set $main $sub
-                                       echo "^$main^ ^$sub^"
+                                       try_remove_previous "$main"
+                                       try_remove_previous "$sub"
                                        main=
                                        sub=
                                fi