vm.c: break from orphan block

* vm.c (rb_vm_search_cf_from_ep): break from orphan block is
  possible condition, but not [BUG].
  [ruby-core:69548] [Bug #11254]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50850 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/ruby/test_enum.rb

@@ -53,7 +53,8 @@ class TestEnumerable < Test::Unit::TestCase
 
     bug5801 = '[ruby-dev:45041]'
     @empty.grep(//)
-    assert_nothing_raised(bug5801) {100.times {@empty.block.call}}
+    block = @empty.block
+    assert_nothing_raised(bug5801) {100.times {block.call}}
 
     a = []
     lambda = ->(x, i) {a << [x, i]}
@@ -201,6 +202,21 @@ class TestEnumerable < Test::Unit::TestCase
     assert_equal(1, @obj.first)
     assert_equal([1, 2, 3], @obj.first(3))
     assert_nil(@empty.first)
+
+    bug5801 = '[ruby-dev:45041]'
+    assert_in_out_err([], <<-'end;', [], /unexpected break/)
+      empty = Object.new
+      class << empty
+        attr_reader :block
+        include Enumerable
+        def each(&block)
+          @block = block
+          self
+        end
+      end
+      empty.first
+      empty.block.call
+    end;
   end
 
   def test_sort
@@ -440,7 +456,8 @@ class TestEnumerable < Test::Unit::TestCase
 
     bug5801 = '[ruby-dev:45040]'
     @empty.take_while {true}
-    assert_nothing_raised(bug5801) {100.times {@empty.block.call}}
+    block = @empty.block
+    assert_nothing_raised(bug5801) {100.times {block.call}}
   end
 
   def test_drop

vm.c

@@ -44,7 +44,7 @@ rb_vm_search_cf_from_ep(const rb_thread_t * const th, rb_control_frame_t *cfp, c
 	    cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp);
 	}
 
-	rb_bug("rb_vm_search_cf_from_ep: no corresponding cfp");
+	return NULL;
     }
 }
 
@@ -1201,6 +1201,12 @@ vm_iter_break(rb_thread_t *th, VALUE val)
     VALUE *ep = VM_CF_PREV_EP(cfp);
     rb_control_frame_t *target_cfp = rb_vm_search_cf_from_ep(th, cfp, ep);
 
+#if 0				/* raise LocalJumpError */
+    if (!target_cfp) {
+	rb_vm_localjump_error("unexpected break", val, TAG_BREAK);
+    }
+#endif
+
     th->state = TAG_BREAK;
     th->errinfo = (VALUE)THROW_DATA_NEW(val, target_cfp, TAG_BREAK);
     TH_JUMP_TAG(th, TAG_BREAK);