From d10451f3fd51f577e704db770de48d05044eb45c Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Mon, 8 Apr 2019 13:47:37 +0000
Subject: [PATCH] object.c: fix searching nested const paths

* object.c (rb_mod_const_get, rb_mod_const_defined): nested const
  paths should not search from toplevel constants.
  [ruby-core:92202] [Bug #15758]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67472 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 object.c                 | 37 ++++++++++++++++++++++++++++++-------
 test/ruby/test_module.rb |  4 ++++
 2 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/object.c b/object.c
index d31755323e..35f07d995d 100644
--- a/object.c
+++ b/object.c
@@ -2526,7 +2526,19 @@ rb_mod_const_get(int argc, VALUE *argv, VALUE mod)
 	    name = ID2SYM(id);
 	    goto wrong_name;
 	}
-	mod = RTEST(recur) ? rb_const_get(mod, id) : rb_const_get_at(mod, id);
+#if 0
+        mod = rb_const_get_0(mod, id, beglen > 0 || !RTEST(recur), RTEST(recur), FALSE);
+#else
+        if (!RTEST(recur)) {
+            mod = rb_const_get_at(mod, id);
+        }
+        else if (beglen == 0) {
+            mod = rb_const_get(mod, id);
+        }
+        else {
+            mod = rb_const_get_from(mod, id);
+        }
+#endif
     }
 
     return mod;
@@ -2674,16 +2686,27 @@ rb_mod_const_defined(int argc, VALUE *argv, VALUE mod)
 	    name = ID2SYM(id);
 	    goto wrong_name;
 	}
-	if (RTEST(recur)) {
-	    if (!rb_const_defined(mod, id))
-		return Qfalse;
-	    mod = rb_const_get(mod, id);
-	}
-	else {
+
+#if 0
+        mod = rb_const_search(mod, id, beglen > 0 || !RTEST(recur), RTEST(recur), FALSE);
+        if (mod == Qundef) return Qfalse;
+#else
+        if (!RTEST(recur)) {
 	    if (!rb_const_defined_at(mod, id))
 		return Qfalse;
 	    mod = rb_const_get_at(mod, id);
 	}
+        else if (beglen == 0) {
+            if (!rb_const_defined(mod, id))
+                return Qfalse;
+            mod = rb_const_get(mod, id);
+        }
+        else {
+            if (!rb_const_defined_from(mod, id))
+                return Qfalse;
+            mod = rb_const_get_from(mod, id);
+        }
+#endif
 
 	if (p < pend && !RB_TYPE_P(mod, T_MODULE) && !RB_TYPE_P(mod, T_CLASS)) {
 	    rb_raise(rb_eTypeError, "%"PRIsVALUE" does not refer to class/module",
diff --git a/test/ruby/test_module.rb b/test/ruby/test_module.rb
index b1ee7b0944..685118544e 100644
--- a/test/ruby/test_module.rb
+++ b/test/ruby/test_module.rb
@@ -296,6 +296,9 @@ class TestModule < Test::Unit::TestCase
   def test_nested_get
     assert_equal Other, Object.const_get([self.class, 'Other'].join('::'))
     assert_equal User::USER, self.class.const_get([User, 'USER'].join('::'))
+    assert_raise(NameError) {
+      Object.const_get([self.class.name, 'String'].join('::'))
+    }
   end
 
   def test_nested_get_symbol
@@ -328,6 +331,7 @@ class TestModule < Test::Unit::TestCase
     assert_send([Object, :const_defined?, [self.class.name, 'Other'].join('::')])
     assert_send([self.class, :const_defined?, 'User::USER'])
     assert_not_send([self.class, :const_defined?, 'User::Foo'])
+    assert_not_send([Object, :const_defined?, [self.class.name, 'String'].join('::')])
   end
 
   def test_nested_defined_symbol