diff --git a/ChangeLog b/ChangeLog
index bd70e5d78b..0340559143 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sat May 26 00:38:21 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* eval.c (ruby_exec_internal): do nothing if no code.
+
+	* compile.c (rb_iseq_compile): check node if NULL before check
+	  nd_type.  [ruby-talk:252956]
+
 Sat May 26 00:05:22 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 
diff --git a/compile.c b/compile.c
index c539e93050..0c5770d31a 100644
--- a/compile.c
+++ b/compile.c
@@ -144,7 +144,10 @@ rb_iseq_compile(VALUE self, NODE *node)
     rb_iseq_t *iseq;
     GetISeqPtr(self, iseq);
 
-    if (nd_type(node) == NODE_SCOPE) {
+    if (node == 0) {
+	COMPILE(ret, "nil", node);
+    }
+    else if (nd_type(node) == NODE_SCOPE) {
 	/* iseq type of top, method, class, block */
 	set_local_table(iseq, node->nd_tbl);
 	set_arguments(iseq, ret, node->nd_args);
@@ -197,9 +200,6 @@ rb_iseq_compile(VALUE self, NODE *node)
 	else if (iseq->type == ISEQ_TYPE_DEFINED_GUARD) {
 	    COMPILE(ret, "defined guard", node);
 	}
-	else if (node == 0) {
-	    COMPILE(ret, "nil", node);
-	}
 	else {
 	    rb_bug("unknown scope");
 	}
diff --git a/eval.c b/eval.c
index 571b84a57d..327cfbfd63 100644
--- a/eval.c
+++ b/eval.c
@@ -204,6 +204,8 @@ ruby_exec_internal(void)
 {
     int state;
     VALUE val;
+
+    if (!ruby_eval_tree) return 0;
     PUSH_TAG();
     if ((state = EXEC_TAG()) == 0) {
 	GET_THREAD()->base_block = 0;