object.c: fix prepend cmp

* object.c (rb_class_inherited_p): search the corresponding
  ancestor to prepended module from prepending class itself.
  [ruby-core:72493] [Bug #11878]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53380 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 2 insertions, 5 deletions

diff --git a/object.c b/object.c
index 65521e2146..53354e928b 100644
--- a/object.c
+++ b/object.c
@@ -1549,18 +1549,15 @@ rb_mod_eqq(VALUE mod, VALUE arg)
 VALUE
 rb_class_inherited_p(VALUE mod, VALUE arg)
 {
-    VALUE start = mod;
-
     if (mod == arg) return Qtrue;
     if (!CLASS_OR_MODULE_P(arg) && !RB_TYPE_P(arg, T_ICLASS)) {
 	rb_raise(rb_eTypeError, "compared with non class/module");
     }
-    arg = RCLASS_ORIGIN(arg);
-    if (class_search_ancestor(mod, arg)) {
+    if (class_search_ancestor(mod, RCLASS_ORIGIN(arg))) {
 	return Qtrue;
     }
     /* not mod < arg; check if mod > arg */
-    if (class_search_ancestor(arg, start)) {
+    if (class_search_ancestor(arg, mod)) {
 	return Qfalse;
     }
     return Qnil;