Fix exec_list::move_nodes_to when the source list is empty

1 files changed, 12 insertions, 8 deletions

diff --git a/list.h b/list.h
index 33b038ce8d..054be7ed43 100644
--- a/list.h
+++ b/list.h
@@ -273,14 +273,18 @@ struct exec_list {
     */
    void move_nodes_to(exec_list *target)
    {
-      target->head = head;
-      target->tail = NULL;
-      target->tail_pred = tail_pred;
-
-      target->head->prev = (exec_node *) &target->head;
-      target->tail_pred->next = (exec_node *) &target->tail;
-
-      make_empty();
+      if (is_empty()) {
+	 target->make_empty();
+      } else {
+	 target->head = head;
+	 target->tail = NULL;
+	 target->tail_pred = tail_pred;
+
+	 target->head->prev = (exec_node *) &target->head;
+	 target->tail_pred->next = (exec_node *) &target->tail;
+
+	 make_empty();
+      }
    }
 
    exec_list_iterator iterator()