nix why-depends: Fix shortest path calculation

This was completely broken since d8972317fc4314864619cadd5620ae780da657a3.

1 files changed, 5 insertions, 3 deletions

diff --git a/src/nix/why-depends.cc b/src/nix/why-depends.cc
index 167c974ee..49da01c0a 100644
--- a/src/nix/why-depends.cc
+++ b/src/nix/why-depends.cc
@@ -106,7 +106,11 @@ struct CmdWhyDepends : SourceExprCommand
         std::map<StorePath, Node> graph;
 
         for (auto & path : closure)
-            graph.emplace(path, Node { .path = path, .refs = store->queryPathInfo(path)->references });
+            graph.emplace(path, Node {
+                .path = path,
+                .refs = store->queryPathInfo(path)->references,
+                .dist = path == dependencyPath ? 0 : inf
+            });
 
         // Transpose the graph.
         for (auto & node : graph)
@@ -115,8 +119,6 @@ struct CmdWhyDepends : SourceExprCommand
 
         /* Run Dijkstra's shortest path algorithm to get the distance
            of every path in the closure to 'dependency'. */
-        graph.emplace(dependencyPath, Node { .path = dependencyPath, .dist = 0 });
-
         std::priority_queue<Node *> queue;
 
         queue.push(&graph.at(dependencyPath));