[Bug #20900] Warn deprecated constant when removing

Author: nobu

spec/ruby/core/module/deprecate_constant_spec.rb

@@ -44,6 +44,15 @@
     end
   end
 
+  ruby_bug '#20900', ''...'3.4' do
+    describe "when removing the deprecated module" do
+      it "warns with a message" do
+        @module.deprecate_constant :PUBLIC1
+        -> { @module.module_eval {remove_const :PUBLIC1} }.should complain(/warning: constant .+::PUBLIC1 is deprecated/)
+      end
+    end
+  end
+
   it "accepts multiple symbols and strings as constant names" do
     @module.deprecate_constant "PUBLIC1", :PUBLIC2
 

test/ruby/test_module.rb

@@ -2148,9 +2148,8 @@ def test_deprecate_constant
       Warning[:deprecated] = false
       Class.new(c)::FOO
     end
-    assert_warn('') do
-      Warning[:deprecated] = false
-      c.class_eval "FOO"
+    assert_warn(/deprecated/) do
+      c.class_eval {remove_const "FOO"}
     end
   end
 

variable.c

@@ -3280,6 +3280,7 @@ rb_const_remove(VALUE mod, ID id)
         undefined_constant(mod, ID2SYM(id));
     }
 
+    rb_const_warn_if_deprecated(ce, mod, id);
     rb_clear_constant_cache_for_id(id);
 
     val = ce->value;