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

  1.instance_eval { undef to_s } causes SEGV before this fix.
* test/ruby/test_undef.rb: new tests for undef.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@25831 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 3 insertions, 0 deletions

diff --git a/vm_method.c b/vm_method.c
index d1c68b58f3..215db50080 100644
--- a/vm_method.c
+++ b/vm_method.c
@@ -574,6 +574,9 @@ rb_undef(VALUE klass, ID id)
 {
     rb_method_entry_t *me;
 
+    if (NIL_P(klass)) {
+	rb_raise(rb_eTypeError, "no class to undef method");
+    }
     if (rb_vm_cbase() == rb_cObject && klass == rb_cObject) {
 	rb_secure(4);
     }