merges r25494 from trunk into ruby_1_9_1.

adds a test case for the change
--
* vm.c (invoke_block_from_c): return Qnil when its iseq is
  SPECIAL CONST. [ruby-core:26335]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_1@26506 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 3 insertions, 1 deletions

diff --git a/vm.c b/vm.c
index f357156993..dfdcb17137 100644
--- a/vm.c
+++ b/vm.c
@@ -493,7 +493,9 @@ invoke_block_from_c(rb_thread_t *th, const rb_block_t *block,
 		    VALUE self, int argc, const VALUE *argv,
 		    const rb_block_t *blockptr, const NODE *cref)
 {
-    if (BUILTIN_TYPE(block->iseq) != T_NODE) {
+    if (SPECIAL_CONST_P(block->iseq))
+	return Qnil;
+    else if (BUILTIN_TYPE(block->iseq) != T_NODE) {
 	const rb_iseq_t *iseq = block->iseq;
 	const rb_control_frame_t *cfp;
 	int i, opt_pc, arg_size = iseq->arg_size;