merge revision(s) 58077,58229: [Backport #13358]

	ostruct.rb: fix OpenStruct.allocate

	* lib/ostruct.rb (OpenStruct.allocate): initialize an instance
	  variable directly, without calling `intialize` method which may
	  be overridden in a subclass.  [ruby-core:80292] [Bug #13358]
	ostruct.rb: improve fix for OpenStruct.allocate + #respond_to?

	* lib/ostruct.rb (OpenStruct#respond_to_missing?): this makes
	  OpenStruct#respond_to? works on any OpenStruct instance,
	  just like Kernel#respond_to? does, without workarounds.
	  [ruby-core:80292] [Bug #13358]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@59407 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 11 insertions, 5 deletions

diff --git a/lib/ostruct.rb b/lib/ostruct.rb
index 417ecf62b3..1d42321b66 100644
--- a/lib/ostruct.rb
+++ b/lib/ostruct.rb
@@ -71,9 +71,6 @@
 # of these properties compared to using a Hash or a Struct.
 #
 class OpenStruct
-  class << self # :nodoc:
-    alias allocate new
-  end
 
   #
   # Creates a new OpenStruct object.  By default, the resulting OpenStruct
@@ -191,7 +188,7 @@ class OpenStruct
 
   def respond_to_missing?(mid, include_private = false)
     mname = mid.to_s.chomp("=").to_sym
-    @table.key?(mname) || super
+    @table&.key?(mname) || super
   end
 
   def method_missing(mid, *args) # :nodoc:
diff --git a/test/ostruct/test_ostruct.rb b/test/ostruct/test_ostruct.rb
index 7df5200ca1..b9bbaace55 100644
--- a/test/ostruct/test_ostruct.rb
+++ b/test/ostruct/test_ostruct.rb
@@ -183,4 +183,13 @@ class TC_OpenStruct < Test::Unit::TestCase
     os.foo = 44
     assert_equal(43, os.foo)
   end
+
+  def test_allocate_subclass
+    bug = '[ruby-core:80292] [Bug #13358] allocate should not call initialize'
+    c = Class.new(OpenStruct) {
+      def initialize(x,y={})super(y);end
+    }
+    os = assert_nothing_raised(ArgumentError, bug) {c.allocate}
+    assert_instance_of(c, os)
+  end
 end
diff --git a/version.h b/version.h
index 3731e5bf2c..e95ed8a70f 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.4.2"
 #define RUBY_RELEASE_DATE "2017-07-23"
-#define RUBY_PATCHLEVEL 158
+#define RUBY_PATCHLEVEL 159
 
 #define RUBY_RELEASE_YEAR 2017
 #define RUBY_RELEASE_MONTH 7