3 files changed, 40 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog
index 4c64fe8480..1d122fdbdb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sun Jul 10 15:30:00 2011  Kenta Murata  <mrkn@mrkn.jp>
+
+	* load.c (rb_f_autoload): prevent to autoload for singleton
+	  classes.  fixes [Bug #4886] [ruby-dev:43816]
+
+	* bootstraptest/test_autoload.rb: add tests for the above change.
+
 Sun Jul 10 15:09:17 2011  Shota Fukumori  <sorah@tubusu.net>
 
 	* lib/test/unit/assertions.rb: Import documentation patch by Justin
diff --git a/bootstraptest/test_autoload.rb b/bootstraptest/test_autoload.rb
index b781fdb7e9..e8df6684b6 100644
--- a/bootstraptest/test_autoload.rb
+++ b/bootstraptest/test_autoload.rb
@@ -1,4 +1,36 @@
 assert_equal 'ok', %q{
+  File.unlink('zzz.rb') if File.file?('zzz.rb')
+  instance_eval do
+    autoload :ZZZ, './zzz.rb'
+    begin
+      ZZZ
+    rescue LoadError
+      :ok
+    end
+  end
+}, '[ruby-dev:43816]'
+
+assert_equal 'ok', %q{
+  open('zzz.rb', 'w') {|f| f.puts '' }
+  instance_eval do
+    autoload :ZZZ, './zzz.rb'
+    begin
+      ZZZ
+    rescue NameError
+      :ok
+    end
+  end
+}, '[ruby-dev:43816]'
+
+assert_equal 'ok', %q{
+  open('zzz.rb', 'w') {|f| f.puts 'class ZZZ; def self.ok;:ok;end;end'}
+  instance_eval do
+    autoload :ZZZ, './zzz.rb'
+    ZZZ.ok
+  end
+}, '[ruby-dev:43816]'
+
+assert_equal 'ok', %q{
   open("zzz.rb", "w") {|f| f.puts "class ZZZ; def self.ok;:ok;end;end"}
   autoload :ZZZ, "./zzz.rb"
   ZZZ.ok
diff --git a/load.c b/load.c
index b819bf37f9..62e2cac4c6 100644
--- a/load.c
+++ b/load.c
@@ -722,7 +722,7 @@ rb_mod_autoload_p(VALUE mod, VALUE sym)
 static VALUE
 rb_f_autoload(VALUE obj, VALUE sym, VALUE file)
 {
-    VALUE klass = rb_vm_cbase();
+    VALUE klass = rb_class_real(rb_vm_cbase());
     if (NIL_P(klass)) {
 	rb_raise(rb_eTypeError, "Can not set autoload on singleton class");
     }