diff --git a/ChangeLog b/ChangeLog
index 5b1650d59d..d58142fdbd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+Thu Oct  2 01:32:46 2003  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* eval.c (rb_f_block_given_p): real required condition is
+	  ruby_frame->prev->iter == ITER_CUR.
+
+	* eval.c (rb_block_given_p): ditto.
+
+	* eval.c (block_pass): update ruby_frame->iter only when previous
+	  value is ITER_NOT.
+
 Thu Oct  2 01:02:35 2003  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* variable.c (rb_const_defined_at): should exclude constants from
diff --git a/eval.c b/eval.c
index 622bbeff65..7c9ede5cb6 100644
--- a/eval.c
+++ b/eval.c
@@ -4002,7 +4002,7 @@ rb_jump_tag(tag)
 int
 rb_block_given_p()
 {
-    if (ruby_frame->iter && ruby_block)
+    if (ruby_frame->iter == ITER_CUR && ruby_block)
 	return Qtrue;
     return Qfalse;
 }
@@ -4016,7 +4016,7 @@ rb_iterator_p()
 static VALUE
 rb_f_block_given_p()
 {
-    if (ruby_frame->prev && ruby_frame->prev->iter && ruby_block)
+    if (ruby_frame->prev && ruby_frame->prev->iter == ITER_CUR && ruby_block)
 	return Qtrue;
     return Qfalse;
 }
@@ -7244,7 +7244,8 @@ block_pass(self, node)
     _block.outer = ruby_block;
     ruby_block = &_block;
     PUSH_ITER(ITER_PRE);
-    ruby_frame->iter = ITER_PRE;
+    if (ruby_frame->iter == ITER_NOT)
+	ruby_frame->iter = ITER_PRE;
 
     PUSH_TAG(PROT_ITER);
     state = EXEC_TAG();