Fixes #4792 (Duplicate definition since 2.6.1 upgrade)

The evaluate_definitions method was first figuring out which resources
needed to be evaluated (using unevaluated_resources), and then
evaluating them one by one.  As a result, if evaluating one resource
triggered another resource to be evaluated, the latter resource could
get evaluated twice.  This bug could occur, for example, if both
resources were classes that were included into the node by an external
node classifier, and if the first of the two classes included the
second.

Modified Resource#evaluate to be idempotent.

Also added an integration test to verify the fix.

2 files changed, 22 insertions, 0 deletions

diff --git a/lib/puppet/parser/resource.rb b/lib/puppet/parser/resource.rb
index e34f284fc..c007d4dbe 100644
--- a/lib/puppet/parser/resource.rb
+++ b/lib/puppet/parser/resource.rb
@@ -64,6 +64,7 @@ class Puppet::Parser::Resource < Puppet::Resource
 
   # Retrieve the associated definition and evaluate it.
   def evaluate
+    return if evaluated?
     @evaluated = true
     if klass = resource_type and ! builtin_type?
       finish
diff --git a/spec/integration/parser/compiler_spec.rb b/spec/integration/parser/compiler_spec.rb
index 9158ad1c2..f80221e3d 100755
--- a/spec/integration/parser/compiler_spec.rb
+++ b/spec/integration/parser/compiler_spec.rb
@@ -27,6 +27,27 @@ describe Puppet::Parser::Compiler do
     @compiler.catalog.version.should == version
   end
 
+  it "should not create duplicate resources when a class is referenced both directly and indirectly by the node classifier (4792)" do
+    Puppet[:code] = <<-PP
+      class foo
+      {
+        notify { foo_notify: }
+        include bar
+      }
+      class bar
+      {
+        notify { bar_notify: }
+      }
+    PP
+
+    @node.stubs(:classes).returns(['foo', 'bar'])
+
+    catalog = Puppet::Parser::Compiler.compile(@node)
+
+    catalog.resource("Notify[foo_notify]").should_not be_nil
+    catalog.resource("Notify[bar_notify]").should_not be_nil
+  end
+
   describe "when resolving class references" do
     it "should favor local scope, even if there's an included class in topscope" do
       Puppet[:code] = <<-PP