From f3660b1c8cba8e701689c82fc3fcaf3a3b8283da Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <e.dolstra@tudelft.nl>
Date: Tue, 12 Apr 2005 10:51:00 +0000
Subject: [PATCH] * Garbage collector fix: allow deletion of paths that have
 invalid   (but substitutable) referers.

---
 src/libstore/store.cc | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/libstore/store.cc b/src/libstore/store.cc
index 4e531bc41..d61c3e454 100644
--- a/src/libstore/store.cc
+++ b/src/libstore/store.cc
@@ -737,10 +737,10 @@ void deleteFromStore(const Path & _path)
     Transaction txn(nixDB);
     if (isValidPathTxn(txn, path)) {
         PathSet referers = getReferers(txn, path);
-        if (referers.size() > 1 ||
-            (referers.size() == 1 &&
-                *referers.begin() != path))
-            throw Error(format("cannot delete path `%1%' because it is in use") % path);
+        for (PathSet::iterator i = referers.begin();
+             i != referers.end(); ++i)
+            if (*i != path && isValidPathTxn(txn, *i))
+                throw Error(format("cannot delete path `%1%' because it is in use by path `%2%'") % path % *i);
         invalidatePath(txn, path);
     }
     txn.commit();