* enumerator.c: Fix state handling for Lazy#drop_while

[bug #7696] [bug #7691]

* test/ruby/test_lazy_enumerator.rb: test for above

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38921 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

enumerator.c

@@ -1754,12 +1754,11 @@ lazy_drop(VALUE obj, VALUE n)
 static VALUE
 lazy_drop_while_func(VALUE val, VALUE args, int argc, VALUE *argv)
 {
-    NODE *memo = RNODE(args);
-
-    if (!memo->u3.state && !RTEST(rb_yield_values2(argc - 1, &argv[1]))) {
-	memo->u3.state = TRUE;
+    VALUE memo = rb_ivar_get(argv[0], id_memo);
+    if (NIL_P(memo) && !RTEST(rb_yield_values2(argc - 1, &argv[1]))) {
+	rb_ivar_set(argv[0], id_memo, memo = Qtrue);
     }
-    if (memo->u3.state) {
+    if (memo == Qtrue) {
 	rb_funcall2(argv[0], id_yield, argc - 1, argv + 1);
     }
     return Qnil;
@@ -1768,14 +1767,11 @@ lazy_drop_while_func(VALUE val, VALUE args, int argc, VALUE *argv)
 static VALUE
 lazy_drop_while(VALUE obj)
 {
-    NODE *memo;
-
     if (!rb_block_given_p()) {
 	rb_raise(rb_eArgError, "tried to call lazy drop_while without a block");
     }
-    memo = NEW_MEMO(0, 0, FALSE);
     return lazy_set_method(rb_block_call(rb_cLazy, id_new, 1, &obj,
-					 lazy_drop_while_func, (VALUE) memo),
+					 lazy_drop_while_func, 0),
 			   Qnil, 0);
 }
 

test/ruby/test_lazy_enumerator.rb

@@ -250,6 +250,13 @@ class TestLazyEnumerator < Test::Unit::TestCase
     assert_equal([*(1..5)]*5, take5.flat_map{take5}.force, bug7696)
   end
 
+  def test_drop_while_nested
+    bug7696 = '[ruby-core:51470]'
+    a = Step.new(1..10)
+    drop5 = a.lazy.drop_while{|x| x < 6}
+    assert_equal([*(6..10)]*5, drop5.flat_map{drop5}.force, bug7696)
+  end
+
   def test_take_rewound
     bug7696 = '[ruby-core:51470]'
     e=(1..42).lazy.take(2)