* vm_method.c (rb_alias): should raise TypeError if klass is nil.

  1.instance_eval { alias to_string to_s } causes SEGV before this
  fix.
* test/ruby/test_alias.rb (test_special_const_alias): ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@25826 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 4 insertions, 0 deletions

diff --git a/vm_method.c b/vm_method.c
index 557583f5aa..d1c68b58f3 100644
--- a/vm_method.c
+++ b/vm_method.c
@@ -857,6 +857,10 @@ rb_alias(VALUE klass, ID name, ID def)
 {
     rb_method_entry_t *orig_me;
 
+    if (NIL_P(klass)) {
+	rb_raise(rb_eTypeError, "no class to make alias");
+    }
+
     rb_frozen_class_p(klass);
     if (klass == rb_cObject) {
 	rb_secure(4);