From a3e9a02ae67cf1e55b29afc63fec2615198c08d5 Mon Sep 17 00:00:00 2001
From: Jim Weirich <jim.weirich@gmail.com>
Date: Thu, 21 Feb 2013 00:19:54 -0800
Subject: [PATCH] Switch to hash for recording already seen tasks in
 all_prerequisite_tasks.

---
 lib/rake/task.rb | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/lib/rake/task.rb b/lib/rake/task.rb
index d674852d9..d9ce00356 100644
--- a/lib/rake/task.rb
+++ b/lib/rake/task.rb
@@ -65,14 +65,17 @@ def lookup_prerequisite(prerequisite_name)
     # prerequisites.
     # Includes self when cyclic dependencies are found.
     def all_prerequisite_tasks
-      fetch_prerequisites
+      seen = {}
+      collect_prerequisites(seen)
+      seen.values
     end
 
-    def fetch_prerequisites(list=[])
+    def collect_prerequisites(seen)
       prerequisite_tasks.each do |pre|
-        list << pre and pre.fetch_prerequisites(list) unless list.include?(pre)
+        next if seen[pre.name]
+        seen[pre.name] = pre
+        pre.collect_prerequisites(seen)
       end
-      list
     end
     protected :fetch_prerequisites