variable.c (generic_ivar_remove): return original value

This fixes a bug introduced in r50678
("variable.c: use indices for generic ivars")
and does not affect any released version of Ruby

* variable.c (generic_ivar_remove): adjust type, set valp
  (rb_obj_remove_instance_variable): simplify call
* test/ruby/test_object.rb (test_remove_instance_variable):
  expand for implementation details

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52378 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 16 insertions, 4 deletions

diff --git a/test/ruby/test_object.rb b/test/ruby/test_object.rb
index 5ba44c8699..b0e561a206 100644
--- a/test/ruby/test_object.rb
+++ b/test/ruby/test_object.rb
@@ -232,10 +232,22 @@ class TestObject < Test::Unit::TestCase
   end
 
   def test_remove_instance_variable
-    o = Object.new
-    o.instance_eval { @foo = :foo }
-    o.remove_instance_variable(:@foo)
-    assert_equal(false, o.instance_variable_defined?(:@foo))
+    { 'T_OBJECT' => Object.new,
+      'T_CLASS,T_MODULE' => Class.new(Object),
+      'generic ivar' => '',
+    }.each do |desc, o|
+      assert_raises(NameError, "#{desc} iv removal raises before set") do
+        o.remove_instance_variable(:@foo)
+      end
+      o.instance_eval { @foo = :foo }
+      assert_equal(:foo, o.remove_instance_variable(:@foo),
+                   "#{desc} iv removal returns original value")
+      assert_equal(false, o.instance_variable_defined?(:@foo),
+                   "#{desc} iv removed succesfully")
+      assert_raises(NameError, "#{desc} iv removal raises after removal") do
+        o.remove_instance_variable(:@foo)
+      end
+    end
   end
 
   def test_convert_string