Merge pull request #2196 from herwinw/kernel_warn_with_verbose_nil

spec/core/kernel/warn_spec.rb

@@ -43,12 +43,10 @@
   end
 
   it "does not call #write on $stderr if $VERBOSE is nil" do
-    NATFIXME 'does not call #write on $stderr if $VERBOSE is nil', exception: SpecFailedException do
-      -> {
-        $VERBOSE = nil
-        warn("this is some simple text")
-      }.should output(nil, "")
-    end
+    -> {
+      $VERBOSE = nil
+      warn("this is some simple text")
+    }.should output(nil, "")
   end
 
   it "writes each argument on a line when passed multiple arguments" do

src/kernel.rb

@@ -57,6 +57,7 @@ def rand(*args)
   end
 
   def warn(*msgs, category: nil, uplevel: nil)
+    return if $VERBOSE.nil?
     if !category.nil? && !category.is_a?(Symbol)
       category = category.to_sym if category.respond_to?(:to_sym)
       raise TypeError, "no implicit conversion of #{category.class} into Symbol" unless category.is_a?(Symbol)