check_funcall_missing() should call respond_to_missing?(name, priv=true)

* Improve spec rather than constrain implementation.
* Coercion ignores visibility in Ruby.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59982 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

spec/ruby/core/array/flatten_spec.rb

@@ -111,18 +111,34 @@ describe "Array#flatten" do
       lambda { [@obj].flatten }.should raise_error(TypeError)
     end
 
+    ruby_version_is ""..."2.5" do
+      it "calls respond_to_missing?(:to_ary, false) to try coercing" do
+        def @obj.respond_to_missing?(*args) ScratchPad << args; false end
+        [@obj].flatten.should == [@obj]
+        ScratchPad.recorded.should == [[:to_ary, false]]
+      end
+    end
+
+    ruby_version_is "2.5" do
+      it "calls respond_to_missing?(:to_ary, true) to try coercing" do
+        def @obj.respond_to_missing?(*args) ScratchPad << args; false end
+        [@obj].flatten.should == [@obj]
+        ScratchPad.recorded.should == [[:to_ary, true]]
+      end
+    end
+
     it "does not call #to_ary if not defined when #respond_to_missing? returns false" do
-      def @obj.respond_to_missing?(*args) ScratchPad << args; false end
+      def @obj.respond_to_missing?(name, priv) ScratchPad << name; false end
 
       [@obj].flatten.should == [@obj]
-      ScratchPad.recorded.should == [[:to_ary, false]]
+      ScratchPad.recorded.should == [:to_ary]
     end
 
     it "calls #to_ary if not defined when #respond_to_missing? returns true" do
-      def @obj.respond_to_missing?(*args) ScratchPad << args; true end
+      def @obj.respond_to_missing?(name, priv) ScratchPad << name; true end
 
       lambda { [@obj].flatten }.should raise_error(NoMethodError)
-      ScratchPad.recorded.should == [[:to_ary, false]]
+      ScratchPad.recorded.should == [:to_ary]
     end
 
     it "calls #method_missing if defined" do

vm_eval.c

@@ -315,8 +315,6 @@ check_funcall_exec(struct rescue_funcall_args *args)
 			     args->me, args->argc, args->argv);
 }
 
-#define PRIV Qfalse	 /* TODO: for rubyspec now, should be Qtrue */
-
 static VALUE
 check_funcall_failed(struct rescue_funcall_args *args, VALUE e)
 {
@@ -361,7 +359,7 @@ check_funcall_missing(rb_thread_t *th, VALUE klass, VALUE recv, ID mid, int argc
     VALUE ret = Qundef;
 
     ret = basic_obj_respond_to_missing(th, klass, recv,
-				       ID2SYM(mid), PRIV);
+				       ID2SYM(mid), Qtrue);
     if (!RTEST(ret)) return def;
     args.respond = respond > 0;
     args.respond_to_missing = (ret != Qundef);