From 890f02e7fed99149ebace28e8fade62a2aff0110 Mon Sep 17 00:00:00 2001
From: Markus Schirp <mbj@seonic.net>
Date: Wed, 1 Aug 2012 16:58:29 +0200
Subject: [PATCH] Handle 18 vs 19-mode differencies for if-statement

---
 lib/mutant.rb                                        | 12 ++++++++++++
 lib/mutant/mutator/if_statement.rb                   |  4 ++++
 .../mutator/{if => if_statement}/mutation_spec.rb    |  8 +++++++-
 3 files changed, 23 insertions(+), 1 deletion(-)
 rename spec/unit/mutant/mutator/{if => if_statement}/mutation_spec.rb (71%)

diff --git a/lib/mutant.rb b/lib/mutant.rb
index 9148aaa3..df61d78b 100644
--- a/lib/mutant.rb
+++ b/lib/mutant.rb
@@ -19,6 +19,18 @@ module Mutant
   def self.deep_clone(object)
     Marshal.load(Marshal.dump(object))
   end
+  
+  # Check for ruby-1.8 mode
+  #
+  # @return [true]
+  #   returns true if running under 1.8 mode
+  #
+  # @return [false]
+  #   returns false otherwise
+  #
+  def self.on_18?
+    RUBY_VERSION == '1.8.7'
+  end
 end
 
 require 'mutant/support/abstract'
diff --git a/lib/mutant/mutator/if_statement.rb b/lib/mutant/mutator/if_statement.rb
index 1517c5ec..867ea6f7 100644
--- a/lib/mutant/mutator/if_statement.rb
+++ b/lib/mutant/mutator/if_statement.rb
@@ -69,6 +69,10 @@ module Mutant
       # capture literal symbol.
       #
       def invert(node)
+        if Mutant.on_18?
+          return new(Rubinius::AST::Not,node)
+        end
+
         new_send(node,:'!')
       end
 
diff --git a/spec/unit/mutant/mutator/if/mutation_spec.rb b/spec/unit/mutant/mutator/if_statement/mutation_spec.rb
similarity index 71%
rename from spec/unit/mutant/mutator/if/mutation_spec.rb
rename to spec/unit/mutant/mutator/if_statement/mutation_spec.rb
index 142ed2bd..140b3472 100644
--- a/spec/unit/mutant/mutator/if/mutation_spec.rb
+++ b/spec/unit/mutant/mutator/if_statement/mutation_spec.rb
@@ -10,7 +10,13 @@ describe Mutant::Mutator, 'if statement' do
     mutants << 'if condition; true; else false; end'
 
     # Invert condition
-    mutants << 'if !self.condition; true; else false; end'
+    if Mutant.on_18?
+      # Explicitly define ast as 18-mode does swap if and else on parsing when negation condition is 
+      # present in condition.
+      mutants << [:if, [:not, [:call, [:self], :condition, [:arglist]]], [:true], [:false]]
+    else
+      mutants << 'if !self.condition; true; else false; end'
+    end
 
     # Deleted else branch
     mutants << 'if self.condition; true end'