1 files changed, 9 insertions, 3 deletions
diff --git a/src/dyndep.cc b/src/dyndep.cc
index b388e9b..dd4ed09 100644
--- a/src/dyndep.cc
+++ b/src/dyndep.cc
@@ -97,9 +97,15 @@ bool DyndepLoader::UpdateEdge(Edge* edge, Dyndeps const* dyndeps,
   for (std::vector<Node*>::const_iterator i =
            dyndeps->implicit_outputs_.begin();
        i != dyndeps->implicit_outputs_.end(); ++i) {
-    if ((*i)->in_edge() != NULL) {
-      *err = "multiple rules generate " + (*i)->path();
-      return false;
+    if (Edge* old_in_edge = (*i)->in_edge()) {
+      // This node already has an edge producing it.  Fail with an error
+      // unless the edge was generated by ImplicitDepLoader, in which
+      // case we can replace it with the now-known real producer.
+      if (!old_in_edge->generated_by_dep_loader_) {
+        *err = "multiple rules generate " + (*i)->path();
+        return false;
+      }
+      old_in_edge->outputs_.clear();
     }
     (*i)->set_in_edge(edge);
   }