StackOverflowError regarding RubyGems, require(), rubygems/defaults/jruby.rb, and jruby/util.rb

Gem::Specification#dirs (defaults/jruby.rb) -> spec_directories_from_classpath -> require 'jruby/util' -> rubygems -> Gem::Specification#dirs -> ...

diff --git a/lib/ruby/site_ruby/1.8/rubygems/defaults/jruby.rb b/lib/ruby/site_ruby/1.8/rubygems/defaults/jruby.rb
index 3545f18..5f1dc65 100644
--- a/lib/ruby/site_ruby/1.8/rubygems/defaults/jruby.rb
+++ b/lib/ruby/site_ruby/1.8/rubygems/defaults/jruby.rb
@@ -1,4 +1,3 @@
-require 'rubygems/maven_gemify' # Maven support
 require 'rbconfig'
 
 module Gem
diff --git a/lib/ruby/site_ruby/1.8/rubygems/spec_fetcher.rb b/lib/ruby/site_ruby/1.8/rubygems/spec_fetcher.rb
index 28fcb3b..ee735af 100644
--- a/lib/ruby/site_ruby/1.8/rubygems/spec_fetcher.rb
+++ b/lib/ruby/site_ruby/1.8/rubygems/spec_fetcher.rb
@@ -285,3 +285,7 @@ class Gem::SpecFetcher
 
 end
 
+# Load rubygems/maven_gemify.rb here because;
+# * want to require only spec_fetcher is required to avoid circular require.
+# * need to require after spec_fetcher and remote_fetcher to override those definitions.
+require 'rubygems/maven_gemify'

require 'jruby/util'

commit c917125a141a9b7efe16e11029bdabe260af9be6
Author: Evan Phoenix <evan@fallingsnow.net>
Date:   Sat Jun 11 23:13:00 2011 -0700

    - Remove Gem.loaded_path and uses
    
    The test that this was added for got lost and upon restoring it found
    that the existing logic handles the case properly.
    
    Check out test_activate_via_require_respects_loaded_files in
    test_require.rb

diff --git a/lib/rubygems.rb b/lib/rubygems.rb
index 9b40d26..52aff29 100644
--- a/lib/rubygems.rb
+++ b/lib/rubygems.rb
@@ -983,14 +983,6 @@ module Gem
     @suffix_pattern ||= "{#{suffixes.join(',')}}"
   end
 
-  def self.loaded_path? path
-    # TODO: ruby needs a feature to let us query what's loaded in 1.8 and 1.9
-
-    re = /(^|\/)#{Regexp.escape path.to_s}#{Regexp.union(*Gem.suffixes)}$/
-
-    $LOADED_FEATURES.find { |s| s =~ re }
-  end
-
   ##
   # Suffixes for require-able paths.
 
diff --git a/lib/rubygems/custom_require.rb b/lib/rubygems/custom_require.rb
index e0f9753..3430fcf 100755
--- a/lib/rubygems/custom_require.rb
+++ b/lib/rubygems/custom_require.rb
@@ -32,7 +32,7 @@ module Kernel
   # that file has already been loaded is preserved.
 
   def require path
-    if Gem::Specification.unresolved_deps.empty? or Gem.loaded_path? path then
+    if Gem::Specification.unresolved_deps.empty? then
       gem_original_require path
     else
       spec = Gem::Specification.find { |s|

commit 62f395be176de1f412ce5a81fcc094076d800ca1
Author: Hiroshi Nakamura <nahi@ruby-lang.org>
Date:   Thu Feb 2 12:12:45 2012 +0900

    JRUBY-6400, 6407: Fix StackOverflowError under some Gem activation situation
    
    RubyGems seems to expect that we don't invoke custom_require while Gem
    spec scanning.  Our JRuby extension in rubygems/defaults/jruby did
    'require "jruby/util"' while Gem scanning and it caused circular
    custom_require invocation.
    
    Since jruby/util is a small, non invasive library (it defines JRuby
    module, JRuby::Util module and some methods of JRuby::Util), this commit
    simply moved the 'require "jruby/util"' line at the top of
    rubygems/defaults/jruby.rb for loading the library at RubyGems
    initialization time.

diff --git a/lib/ruby/site_ruby/1.8/rubygems/defaults/jruby.rb b/lib/ruby/site_ruby/1.8/rubygems/defaults/jruby.rb
index 20391a0..fdcd019 100644
--- a/lib/ruby/site_ruby/1.8/rubygems/defaults/jruby.rb
+++ b/lib/ruby/site_ruby/1.8/rubygems/defaults/jruby.rb
@@ -1,5 +1,6 @@
 require 'rubygems/config_file'
 require 'rbconfig'
+require 'jruby/util'
 
 module Gem
 
@@ -69,7 +70,6 @@ class Gem::Specification
     end
 
     def spec_directories_from_classpath
-      require 'jruby/util'
       stuff = JRuby::Util.classloader_resources("specifications")
     end
   end

> To be clear, the fix is Headius's.