Fix #1109 - allow empty if or else branches

This changesets allow empty if or else branches:

if true {
} else {
}

It works by emitting on the parser stack an AST node that doesn't
do anything (a no-op). This allows the less intrusive code
as no part of the if evaluation code has been touched.

1 files changed, 20 insertions, 0 deletions

diff --git a/spec/unit/parser/ast/nop.rb b/spec/unit/parser/ast/nop.rb
new file mode 100755
index 000000000..5a7132586
--- /dev/null
+++ b/spec/unit/parser/ast/nop.rb
@@ -0,0 +1,20 @@
+#!/usr/bin/env ruby
+
+require File.dirname(__FILE__) + '/../../../spec_helper'
+
+describe Puppet::Parser::AST::Nop do
+
+    before do
+        @scope = mock 'scope'
+    end
+
+    it "should do nothing on evaluation" do
+        Puppet::Parser::AST.expects(:safeevaluate).never
+        Puppet::Parser::AST::Nop.new({}).evaluate(@scope)
+    end
+
+    it "should not return anything" do
+        Puppet::Parser::AST::Nop.new({}).evaluate(@scope).should be_nil
+    end
+
+end