merge revision(s) r47715: [Backport ruby#10282]

	* object.c (rb_class_real): do not dereference 0 VALUE

	* test/ruby/test_module.rb (test_inspect_segfault):
	  Test case and bug report by Thomas Stratmann.
	  [ruby-core:65214] [Bug ruby#10282]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@47957 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

Author: nagachika

ChangeLog

@@ -1,3 +1,11 @@
+Thu Oct 16 00:20:12 2014  Eric Wong  <[email protected]>
+
+	* object.c (rb_class_real): do not dereference 0 VALUE
+
+	* test/ruby/test_module.rb (test_inspect_segfault):
+	  Test case and bug report by Thomas Stratmann.
+	  [ruby-core:65214] [Bug #10282]
+
 Thu Oct 16 00:10:45 2014  Nobuyoshi Nakada  <[email protected]>
 
 	* signal.c (rb_f_kill): get rid of deadlock as unhandled and

object.c

@@ -203,9 +203,8 @@ rb_obj_not_equal(VALUE obj1, VALUE obj2)
 VALUE
 rb_class_real(VALUE cl)
 {
-    if (cl == 0)
-        return 0;
-    while ((RBASIC(cl)->flags & FL_SINGLETON) || BUILTIN_TYPE(cl) == T_ICLASS) {
+    while (cl &&
+        ((RBASIC(cl)->flags & FL_SINGLETON) || BUILTIN_TYPE(cl) == T_ICLASS)) {
 	cl = RCLASS_SUPER(cl);
     }
     return cl;

test/ruby/test_module.rb

@@ -1957,6 +1957,30 @@ def foo; end
     }
   end
 
+  def test_inspect_segfault
+    bug_10282 = '[ruby-core:65214] [Bug #10282]'
+    assert_separately [], <<-RUBY
+      module ShallowInspect
+        def shallow_inspect
+          "foo"
+        end
+      end
+
+      module InspectIsShallow
+        include ShallowInspect
+        alias_method :inspect, :shallow_inspect
+      end
+
+      class A
+      end
+
+      A.prepend InspectIsShallow
+
+      expect = "#<Method: A(Object)#inspect(shallow_inspect)>"
+      assert_equal expect, A.new.method(:inspect).inspect, "#{bug_10282}"
+    RUBY
+  end
+
   private
 
   def assert_top_method_is_private(method)

version.h

@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.1.4"
 #define RUBY_RELEASE_DATE "2014-10-16"
-#define RUBY_PATCHLEVEL 255
+#define RUBY_PATCHLEVEL 256
 
 #define RUBY_RELEASE_YEAR 2014
 #define RUBY_RELEASE_MONTH 10