ordered_tree: avoid abort if subs is empty

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/lib/ordered_tree.nit b/lib/ordered_tree.nit
index 0b1d383..32cea45 100644 (file)
--- a/lib/ordered_tree.nit
+++ b/lib/ordered_tree.nit
@@ -149,6 +149,7 @@ class OrderedTree[E: Object]
        do
                if not sub.has_key(e) then return
                var subs = sub[e]
+               if subs.is_empty then return
                var last = subs.last
                for e2 in subs do
                        if e2 != last then