Prune would get confused by link packages

1 files changed, 9 insertions, 5 deletions

diff --git a/lib/prune.js b/lib/prune.js
index d2aae8b4a..8217c3a1d 100644
--- a/lib/prune.js
+++ b/lib/prune.js
@@ -15,18 +15,22 @@ function prune (args, cb) {
 }
 
 function prune_ (args, data, cb) {
-  npm.commands.unbuild(prunables(args, data), cb)
+  npm.commands.unbuild(prunables(args, data, []), cb)
 }
 
-function prunables (args, data, cb) {
+function prunables (args, data, seen) {
   var deps = data.dependencies || {}
   return Object.keys(deps).map(function (d) {
-    if (typeof deps[d] !== "object") return null
+    if (typeof deps[d] !== "object"
+        || seen.indexOf(deps[d]) !== -1) return null
+    seen.push(deps[d])
     if (deps[d].extraneous
         && (args.length === 0 || args.indexOf(d) !== -1)) {
-      return deps[d].path
+      var extra = deps[d]
+      delete deps[d]
+      return extra.path
     }
-    return prunables(args, deps[d])
+    return prunables(args, deps[d], seen)
   }).filter(function (d) { return d !== null })
   .reduce(function FLAT (l, r) {
     return l.concat(Array.isArray(r) ? r.reduce(FLAT,[]) : r)