* In nix-store: added query `--referers-closure' that returns the

  closure of the referers relation rather than the references
  relation, i.e., the set of all paths that directly or indirectly
  refer to the given path.  Note that contrary to the references
  closure this set is not fixed; it can change as paths are added to
  or removed from the store.

1 files changed, 6 insertions, 3 deletions

diff --git a/src/libstore/misc.cc b/src/libstore/misc.cc
index dbb9273f7955..802e576512f1 100644
--- a/src/libstore/misc.cc
+++ b/src/libstore/misc.cc
@@ -12,17 +12,20 @@ Derivation derivationFromPath(const Path & drvPath)
 
 
 void computeFSClosure(const Path & storePath,
-    PathSet & paths)
+    PathSet & paths, bool flipDirection)
 {
     if (paths.find(storePath) != paths.end()) return;
     paths.insert(storePath);
 
     PathSet references;
-    queryReferences(storePath, references);
+    if (flipDirection)
+        queryReferers(storePath, references);
+    else
+        queryReferences(storePath, references);
 
     for (PathSet::iterator i = references.begin();
          i != references.end(); ++i)
-        computeFSClosure(*i, paths);
+        computeFSClosure(*i, paths, flipDirection);
 }