fix 1.8 compat regression with const_defined?(name, false)

`const_defined?` allows only a single argument on Ruby 1.8
introduced in 7dc25d8

Author: kares

lib/resque/helpers.rb

@@ -48,14 +48,15 @@ def constantize(camel_cased_word)
           constant.const_get(name)
         else
           candidate = constant.const_get(name)
-          next candidate if constant.const_defined?(name, false)
+          args = Module.method(:const_defined?).arity != 1 ? [false] : []
+          next candidate if constant.const_defined?(name, *args)
           next candidate unless Object.const_defined?(name)
 
           # Go down the ancestors to check it it's owned
           # directly before we reach Object or the end of ancestors.
           constant = constant.ancestors.inject do |const, ancestor|
             break const    if ancestor == Object
-            break ancestor if ancestor.const_defined?(name, false)
+            break ancestor if ancestor.const_defined?(name, *args)
             const
           end
 

test/worker_test.rb

@@ -384,7 +384,7 @@ def self.perform
       assert_equal nil, found
     end
   end
-
+  
   it "cleans up dead worker info on start (crash recovery)" do
     # first we fake out two dead workers
     workerA = Resque::Worker.new(:jobs)
@@ -713,4 +713,13 @@ def self.on_failure_store_exception(exc, *args)
       end
     end
   end
+  
+  it "constantizes" do
+    assert_same Kernel, Resque::Worker.constantize(:Kernel)
+    assert_same MiniTest::Unit::TestCase, Resque::Worker.constantize('MiniTest::Unit::TestCase')
+    assert_raises NameError do
+      Resque::Worker.constantize('Object::MissingConstant')
+    end
+  end
+  
 end