~/Development/OpenSource/ruby
diff --git a/lib/rubygems/core_ext/kernel_require.rb b/lib/rubygems/core_ext/kernel_require.rb
index aa56ab5..472f3cc 100755
--- a/lib/rubygems/core_ext/kernel_require.rb
+++ b/lib/rubygems/core_ext/kernel_require.rb
@@ -22,6 +22,17 @@ module Kernel
     private :gem_original_require
   end
 
+  if defined?(loaded_feature?)
+    def gem_loaded_feature?(path)
+      loaded_feature?(path)
+    end
+  else
+    def gem_loaded_feature?(path)
+      false
+    end
+  end
+  private :gem_loaded_feature?
+
   ##
   # When RubyGems is required, Kernel#require is replaced with our own which
   # is capable of loading gems on demand.
@@ -37,9 +48,10 @@ module Kernel
   # that file has already been loaded is preserved.
 
   def require path
-    RUBYGEMS_ACTIVATION_MONITOR.enter
-
     path = path.to_path if path.respond_to? :to_path
+    return false if gem_loaded_feature?(path)
+
+    RUBYGEMS_ACTIVATION_MONITOR.enter
 
     spec = Gem.find_unresolved_default_spec(path)
     if spec
@@ -138,4 +150,3 @@ def require path
   private :require
 
 end
-
diff --git a/load.c b/load.c
index 1ccd238..9a309dc 100644
--- a/load.c
+++ b/load.c
@@ -524,6 +524,12 @@ rb_provided(const char *feature)
     return rb_feature_provided(feature, 0);
 }
 
+VALUE
+rb_f_loaded_feature(VALUE obj, VALUE fname)
+{
+  return rb_provided(RSTRING_PTR(rb_str_encode_ospath(fname))) ? Qtrue : Qfalse;
+}
+
 int
 rb_feature_provided(const char *feature, const char **loading)
 {
@@ -1202,6 +1208,7 @@ Init_load(void)
     rb_define_method(rb_cModule, "autoload?", rb_mod_autoload_p, 1);
     rb_define_global_function("autoload", rb_f_autoload, 2);
     rb_define_global_function("autoload?", rb_f_autoload_p, 1);
+    rb_define_global_function("loaded_feature?", rb_f_loaded_feature, 1);
 
     ruby_dln_librefs = rb_ary_tmp_new(0);
     rb_gc_register_mark_object(ruby_dln_librefs);