Check for env.rb via ENV_LOADED instead of respond_to?(:require)

The rubygem 'polyglot', which is depended on by Cucumber via Treetop,
redefines the Kernel#require method, making it public instead of
private. This is pretty horrible. Libraries should not break the
behaviour of the stdlib. :(

This commit implements a workaround for that particular issue, with
a test that does the same thing polyglot does.

Closes #287

4 files changed, 26 insertions, 5 deletions

diff --git a/lib/bundler.rb b/lib/bundler.rb
index 6477775139..d32635ab93 100644
--- a/lib/bundler.rb
+++ b/lib/bundler.rb
@@ -87,12 +87,12 @@ module Bundler
         exit!
       end
     end
-    alias setup gem_setup unless Bundler.respond_to?(:setup)
+    alias setup gem_setup unless defined?(Bundler::ENV_LOADED)
 
     def gem_require(*groups)
       setup(*groups).require(*groups)
     end
-    alias require gem_require unless Bundler.respond_to?(:require)
+    alias require gem_require unless defined?(Bundler::ENV_LOADED)
 
     def load
       @load ||= begin
diff --git a/lib/bundler/templates/environment.erb b/lib/bundler/templates/environment.erb
index bca1c247ca..a905af5900 100644
--- a/lib/bundler/templates/environment.erb
+++ b/lib/bundler/templates/environment.erb
@@ -6,6 +6,7 @@ require 'yaml'
 <%= shared_helpers %>
 
 module Bundler
+  ENV_LOADED   = true
   LOCKED_BY    = '<%= Bundler::VERSION %>'
   FINGERPRINT  = <%= gemfile_fingerprint.inspect %>
   HOME         = '<%= Bundler.home %>'
diff --git a/spec/runtime/environment_rb_spec.rb b/spec/runtime/environment_rb_spec.rb
index 73215c1b2a..d2d7ae2f7a 100644
--- a/spec/runtime/environment_rb_spec.rb
+++ b/spec/runtime/environment_rb_spec.rb
@@ -218,7 +218,27 @@ describe "environment.rb file" do
       bundle :lock
 
       bundle %|exec ruby -e "require 'bundler'; Bundler.setup"|
-      err.should == ""
+      err.should be_empty
+    end
+
+    it "handles polyglot making Kernel#require public :(" do
+      install_gemfile <<-G
+        source "file://#{gem_repo1}"
+        gem "rack"
+      G
+
+      ruby <<-RUBY
+        require 'rubygems'
+        module Kernel
+          alias polyglot_original_require require
+          def require(*a, &b)
+            polyglot_original_require(*a, &b)
+          end
+        end
+        require 'bundler'
+        Bundler.require(:foo, :bar)
+      RUBY
+      err.should be_empty
     end
   end
 end
diff --git a/spec/support/builders.rb b/spec/support/builders.rb
index 2145cdc510..6118d89ad4 100644
--- a/spec/support/builders.rb
+++ b/spec/support/builders.rb
@@ -124,11 +124,11 @@ module Spec
         end
 
         build_gem "yard" do |s|
-          s.write "lib/yard.rb", <<-Y
+          s.write "lib/yard.rb", <<-RUBY
             Gem.source_index.find_name('').each do |gem|
               require gem.name
             end
-          Y
+          RUBY
         end
 
         # Test comlicated gem dependencies for install