2 files changed, 11 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog
index 44d8723bdc..5f9a6e9163 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Dec 16 09:14:28 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* parse.y (block_call): block should not be given to yield.
+	  [ruby-core:20583]
+
 Mon Dec 15 23:48:39 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* thread.c (sleep_timeval): cast tv_usec to long to shut up
diff --git a/parse.y b/parse.y
index 2cf9006104..6983a2cdb2 100644
--- a/parse.y
+++ b/parse.y
@@ -3497,7 +3497,12 @@ do_block	: keyword_do_block
 block_call	: command do_block
 		    {
 		    /*%%%*/
-			block_dup_check($1->nd_args, $2);
+			if (nd_type($1) == NODE_YIELD) {
+			    compile_error(PARSER_ARG "block given to yield");
+			}
+			else {
+			    block_dup_check($1->nd_args, $2);
+			}    
 			$2->nd_iter = $1;
 			$$ = $2;
 			fixpos($$, $1);