1 files changed, 25 insertions, 49 deletions

diff --git a/spec/bundler/support/rubygems_version_manager.rb b/spec/bundler/support/rubygems_version_manager.rb
index 356d391c08..854bce890d 100644
--- a/spec/bundler/support/rubygems_version_manager.rb
+++ b/spec/bundler/support/rubygems_version_manager.rb
@@ -8,27 +8,25 @@ class RubygemsVersionManager
   include Spec::Helpers
   include Spec::Path
 
-  def initialize(env_version)
-    @env_version = env_version
+  def initialize(source)
+    @source = source
   end
 
   def switch
     return if use_system?
 
-    unrequire_rubygems_if_needed
-
     switch_local_copy_if_needed
 
-    prepare_environment
+    reexec_if_needed
   end
 
 private
 
   def use_system?
-    @env_version.nil?
+    @source.nil?
   end
 
-  def unrequire_rubygems_if_needed
+  def reexec_if_needed
     return unless rubygems_unrequire_needed?
 
     require "rbconfig"
@@ -37,7 +35,8 @@ private
     ruby << RbConfig::CONFIG["EXEEXT"]
 
     cmd = [ruby, $0, *ARGV].compact
-    cmd[1, 0] = "--disable-gems"
+
+    ENV["RUBYOPT"] = "-I#{local_copy_path.join("lib")} #{ENV["RUBYOPT"]}"
 
     exec(ENV, *cmd)
   end
@@ -47,35 +46,28 @@ private
 
     Dir.chdir(local_copy_path) do
       sys_exec!("git remote update")
-      sys_exec!("git checkout #{target_tag_version} --quiet")
+      sys_exec!("git checkout #{target_tag} --quiet")
     end
-  end
 
-  def prepare_environment
-    $:.unshift File.expand_path("lib", local_copy_path)
+    ENV["RGV"] = local_copy_path.to_s
   end
 
   def rubygems_unrequire_needed?
-    defined?(Gem::VERSION) && Gem::VERSION != target_gem_version
+    !$LOADED_FEATURES.include?(local_copy_path.join("lib/rubygems.rb").to_s)
   end
 
   def local_copy_switch_needed?
-    !env_version_is_path? && target_gem_version != local_copy_version
-  end
-
-  def target_gem_version
-    @target_gem_version ||= resolve_target_gem_version
+    !source_is_path? && target_tag != local_copy_tag
   end
 
-  def target_tag_version
-    @target_tag_version ||= resolve_target_tag_version
+  def target_tag
+    @target_tag ||= resolve_target_tag
   end
 
-  def local_copy_version
-    gemspec_contents = File.read(local_copy_path.join("lib/rubygems.rb"))
-    version_regexp = /VERSION = ["'](.*)["']/
-
-    version_regexp.match(gemspec_contents)[1]
+  def local_copy_tag
+    Dir.chdir(local_copy_path) do
+      sys_exec!("git rev-parse --abbrev-ref HEAD")
+    end
   end
 
   def local_copy_path
@@ -83,7 +75,7 @@ private
   end
 
   def resolve_local_copy_path
-    return expanded_env_version if env_version_is_path?
+    return expanded_source if source_is_path?
 
     rubygems_path = root.join("tmp/rubygems")
 
@@ -95,33 +87,17 @@ private
     rubygems_path
   end
 
-  def env_version_is_path?
-    expanded_env_version.directory?
+  def source_is_path?
+    expanded_source.directory?
   end
 
-  def expanded_env_version
-    @expanded_env_version ||= Pathname.new(@env_version).expand_path(root)
+  def expanded_source
+    @expanded_source ||= Pathname.new(@source).expand_path(root)
   end
 
-  def resolve_target_tag_version
-    return "v#{@env_version}" if @env_version.match(/^\d/)
-
-    return "master" if @env_version == master_gem_version
-
-    @env_version
-  end
-
-  def resolve_target_gem_version
-    return local_copy_version if env_version_is_path?
-
-    return @env_version[1..-1] if @env_version.match(/^v/)
-
-    return master_gem_version if @env_version == "master"
-
-    @env_version
-  end
+  def resolve_target_tag
+    return "v#{@source}" if @source.match(/^\d/)
 
-  def master_gem_version
-    "3.1.0.pre1"
+    @source
   end
 end