Avoid touching key attribute when cloning edge attributes

diff --git a/lib/common/utils.c b/lib/common/utils.c
index 5ba6bd7e4137318b08edaa653f34c5969ba1814b..794a78101afadd5bc319df105785fccbbdb1592a 100644 (file)
--- a/lib/common/utils.c
+++ b/lib/common/utils.c
@@ -1491,6 +1491,7 @@ static edge_t *cloneEdge(edge_t * e, node_t * ct, node_t * ch)
     edge_t *ce = agedge(g, ct, ch);
 
     while ((sym = *list++)) {
+       if (sym->index == 0) continue;
        agxset(ce, sym->index, agxget(e, sym->index));
     }