Remove LoadedFeaturesProxy from my require patch.

no_loaded_features_proxy.diff

diff --git a/load.c b/load.c
index 776dd4d..c5e10ca 100644
--- a/load.c
+++ b/load.c
@@ -52,8 +52,6 @@ VALUE rb_get_expanded_load_path();
 static VALUE rb_cLoadedFeaturesProxy;
 static void rb_rehash_loaded_features();
 static VALUE rb_loaded_features_hook(int, VALUE*, VALUE);
-static void define_loaded_features_proxy();
-static VALUE loaded_features_proxy_new(VALUE);
 
 static st_table * get_loading_table(void);
 static st_table * get_loaded_features_hash(void);
@@ -93,6 +91,16 @@ rb_file_is_ruby(VALUE path)
 	return ext && IS_RBEXT(ext);
 }
 
+/* Attempts to detect whether $LOADED_FEATURES has been manipulated by
+ * a process other than `require`, such as by directly adding an entry to
+ * it. This is typically done by tests and C-extensions. 
+ */
+static int
+rb_loaded_features_changed()
+{
+	return GET_VM()->expected_loaded_features_count != RARRAY_LEN(get_loaded_features());
+}
+
 static int
 rb_file_has_been_required(VALUE expanded_path)
 {
@@ -100,6 +108,11 @@ rb_file_has_been_required(VALUE expanded_path)
 	st_data_t path_key = (st_data_t)RSTRING_PTR(expanded_path);
 	st_table *loaded_features_hash = get_loaded_features_hash();
 
+	if (rb_loaded_features_changed()) { 
+		rb_rehash_loaded_features();
+		rb_clear_cached_expansions();
+	}
+
 	return st_lookup(loaded_features_hash, path_key, &data);
 }
 
@@ -337,49 +350,13 @@ rb_set_cached_expansion(VALUE filename, VALUE expanded)
 	st_insert(filename_expansion_hash, path_key, data);
 }
 
-
-/*
- * $LOADED_FEATURES is exposed publically as an array, but under the covers
- * we also store this data in a hash for fast lookups. So that we can rebuild
- * the hash whenever $LOADED_FEATURES is changed, we wrap the Array class
- * in a proxy that intercepts all data-modifying methods and rebuilds the
- * hash.
- *
- * Note that the list of intercepted methods is currently non-comprehensive
- * --- it only covers modifications made by the ruby and rubyspec test suites.
- */
-static void
-define_loaded_features_proxy()
-{
-	const char* methods_to_hook[] = {"<<", "push", "clear", "replace", "delete"};
-	unsigned int i;
-
-	rb_cLoadedFeaturesProxy = rb_define_class("LoadedFeaturesProxy", rb_cArray);
-	for (i = 0; i < CHAR_ARRAY_LEN(methods_to_hook); ++i) {
-		rb_define_method(
-		    rb_cLoadedFeaturesProxy,
-		    methods_to_hook[i],
-		    rb_loaded_features_hook,
-		    -1);
-	}
-}
-
-static VALUE
-rb_loaded_features_hook(int argc, VALUE *argv, VALUE self)
-{
-	VALUE ret;
-	ret = rb_call_super(argc, argv);
-	rb_rehash_loaded_features();
-	rb_clear_cached_expansions();
-	return ret;
-}
-
 static void
 rb_rehash_loaded_features()
 {
 	int i;
 	VALUE features;
 	VALUE feature;
+	VALUE directory, basename, extension;
 
 	st_table* loaded_features_hash = get_loaded_features_hash();
 
@@ -387,12 +364,38 @@ rb_rehash_loaded_features()
 
 	features = get_loaded_features();
 
+	GET_VM()->expected_loaded_features_count = RARRAY_LEN(features);
 	for (i = 0; i < RARRAY_LEN(features); ++i) {
 		feature = RARRAY_PTR(features)[i];
-		st_insert(
-		    loaded_features_hash,
-		    (st_data_t)ruby_strdup(RSTRING_PTR(feature)),
-		    (st_data_t)rb_barrier_new());
+		if (rb_path_is_absolute(feature)) {
+			st_insert(
+			    loaded_features_hash,
+			    (st_data_t)ruby_strdup(RSTRING_PTR(feature)),
+			    (st_data_t)rb_barrier_new());
+		} else {
+			st_insert(
+			    loaded_features_hash,
+			    (st_data_t)ruby_strdup(RSTRING_PTR(feature)),
+			    (st_data_t)rb_barrier_new());
+			extension = rb_file_extension(feature);
+
+			if (RSTRING_LEN(extension) > 0) {
+				directory = rb_file_dirname(feature);
+
+				basename  = rb_funcall(rb_cFile, rb_intern("basename"), 2,
+							feature, extension);
+
+				if (RSTRING_PTR(directory)[0] == '.') {
+					feature = basename;
+				} else {
+					feature = rb_funcall(rb_cFile, rb_intern("join"), 2, directory, basename);
+				}
+				st_insert(
+				    loaded_features_hash,
+				    (st_data_t)ruby_strdup(RSTRING_PTR(feature)),
+				    (st_data_t)rb_barrier_new());
+			}
+		}
 	}
 }
 
@@ -429,21 +432,6 @@ get_filename_expansion_hash(void)
     return filename_expansion_hash;
 }
 
-/* This is cargo-culted from ary_alloc in array.c. I am sure there is 
- * a much better way to instantiate this class, I just don't know what it is.
- */
-static VALUE
-loaded_features_proxy_new(VALUE klass)
-{
-    NEWOBJ(ary, struct RArray);
-    OBJSETUP(ary, klass, T_ARRAY);
-    FL_SET((ary), RARRAY_EMBED_FLAG);
-    RBASIC(ary)->flags &= ~RARRAY_EMBED_LEN_MASK;
-    RBASIC(ary)->flags |= (0) << RARRAY_EMBED_LEN_SHIFT;
-
-    return (VALUE)ary;
-}
-
 static const char *const loadable_ext[] = {
     ".rb", DLEXT,
 #ifdef DLEXT2
@@ -1030,6 +1018,10 @@ rb_require_safe(VALUE fname, int safe)
 	rb_set_safe_level_force(safe);
 	FilePathValue(fname);
 	rb_set_safe_level_force(0);
+	if (rb_file_has_been_required(fname)) {
+		/* Checks of features provided manually (such as by C-extensions) */
+		result = Qfalse;
+	} else {
 		path = rb_locate_file(fname);
 
 		if (safe >= 1 && OBJ_TAINTED(path)) {
@@ -1055,10 +1047,12 @@ rb_require_safe(VALUE fname, int safe)
 						rb_ary_push(ruby_dln_librefs, LONG2NUM(handle));
 					}
 					rb_provide_feature(path);
+					GET_VM()->expected_loaded_features_count++;
 					result = Qtrue;
 				}
 			}
 		}
+	}
     }
     POP_TAG();
     load_unlock(ftptr, !state);
@@ -1212,9 +1206,8 @@ Init_load()
     rb_define_virtual_variable("$\"", get_loaded_features, 0);
     rb_define_virtual_variable("$LOADED_FEATURES", get_loaded_features, 0);
 
-	define_loaded_features_proxy();
-
-	vm->loaded_features = loaded_features_proxy_new(rb_cLoadedFeaturesProxy);
+	vm->loaded_features = rb_ary_new();
+	vm->expected_loaded_features_count = 0;
 
     rb_define_global_function("load", rb_f_load, -1);
     rb_define_global_function("require", rb_f_require, 1);
diff --git a/test/ruby/test_require.rb b/test/ruby/test_require.rb
index 49a7952..40b4549 100644
--- a/test/ruby/test_require.rb
+++ b/test/ruby/test_require.rb
@@ -413,4 +413,36 @@ class TestRequire < Test::Unit::TestCase
     $:.replace(load_path)
     $".replace(loaded)
   end
+
+  def test_load_c_provided_feature
+    assert !require("enumerator")
+  end
+
+  def test_load_manually_provided_rb
+    # This technique is used in ext/extmk.rb for reasons unknown
+    loaded = $".dup
+    $".clear
+    $" << 'mkmf.rb'
+    %w(
+      mkmf.rb 
+      mkmf
+    ).each do |file|
+      assert !require("#{file}"), "Require of #{file} expected to return false"
+    end
+  ensure
+    $".replace(loaded)
+  end
+
+  def test_load_manually_provided_extension
+    loaded = $".dup
+    $" << 'c_feature.so'
+    %w(
+      c_feature.so
+      c_feature
+    ).each do |file|
+      assert !require("#{file}"), "Require of #{file} expected to return false"
+    end
+  ensure
+    $".replace(loaded)
+  end
 end
diff --git a/vm_core.h b/vm_core.h
index 7818ec0..388934a 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -324,8 +324,12 @@ typedef struct rb_vm_struct {
      * objects so do *NOT* mark this when you GC.
      */
     struct RArray at_exit;
+
+        /* The following three variables are used in load.c as part
+         * of requiring files */
         struct st_table *loaded_features_hash;
         struct st_table *filename_expansion_hash;
+        long expected_loaded_features_count;
 } rb_vm_t;
 
 typedef struct {