Resources of the same name now inherit the attributes of the prior resource - see CHEF-26

Author: adamhjk

chef/lib/chef/recipe.rb

@@ -180,6 +180,8 @@ def method_missing(method_symbol, *args, &block)
           args << @collection
           args << @node
           resource = eval(rname).new(*args)
+          # If we have a resource like this one, we want to steal it's state
+          resource.load_prior_resource
           resource.cookbook_name = @cookbook_name
           resource.recipe_name = @recipe_name
           resource.params = @params

chef/lib/chef/resource.rb

@@ -38,7 +38,7 @@ def initialize(name, collection=nil, node=nil)
         @collection = collection
       else
         @collection = Chef::ResourceCollection.new()
-      end
+      end      
       @node = node ? node : Chef::Node.new
       @noop = nil
       @before = nil
@@ -59,6 +59,21 @@ def initialize(name, collection=nil, node=nil)
       end
     end
 
+    def load_prior_resource
+      begin
+        prior_resource = @collection.lookup(self.to_s)
+        Chef::Log.debug("Setting #{self.to_s} to the state of the prior #{self.to_s}")
+        prior_resource.instance_variables.each do |iv|
+          unless iv == "@source_line"
+            self.instance_variable_set(iv, prior_resource.instance_variable_get(iv))
+          end
+        end
+        true
+      rescue ArgumentError => e
+        true
+      end
+    end
+    
     def supports(args={})
       if args.any?
         @supports = args

example-repository/cookbooks/prior_resource_test/recipes/default.rb

@@ -0,0 +1,27 @@
+#
+# Cookbook Name:: prior_resource_test
+# Recipe:: default
+#
+# Copyright 2009, Example Com
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+# 
+#     http://www.apache.org/licenses/LICENSE-2.0
+# 
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+file "/tmp/prior_resource_test" do
+  backup 16 
+  action :create
+end
+
+file "/tmp/prior_resource_test" do
+  action :delete
+end