* ext/psych/lib/psych/visitors/yaml_tree.rb (accept): use Hash#key?

  when looking up object references to err on the side of cache
  misses.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@30933 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 6 insertions, 3 deletions

diff --git a/ext/psych/lib/psych/visitors/yaml_tree.rb b/ext/psych/lib/psych/visitors/yaml_tree.rb
index e7d182f707..6d6f96ea32 100644
--- a/ext/psych/lib/psych/visitors/yaml_tree.rb
+++ b/ext/psych/lib/psych/visitors/yaml_tree.rb
@@ -70,9 +70,12 @@ module Psych
 
       def accept target
         # return any aliases we find
-        if node = @st[target.object_id]
-          node.anchor = target.object_id.to_s
-          return @emitter.alias target.object_id.to_s
+        if @st.key? target.object_id
+          oid         = target.object_id
+          node        = @st[oid]
+          anchor      = oid.to_s
+          node.anchor = oid
+          return @emitter.alias oid
         end
 
         if target.respond_to?(:to_yaml)