Warn when passing a non-literal block to Kernel#lambda

Implements [Feature #15973]

2 files changed, 7 insertions, 2 deletions

diff --git a/test/ruby/test_iterator.rb b/test/ruby/test_iterator.rb
index 54c095338f..820d5591c1 100644
--- a/test/ruby/test_iterator.rb
+++ b/test/ruby/test_iterator.rb
@@ -339,8 +339,7 @@ class TestIterator < Test::Unit::TestCase
     marity_test(:marity_test)
     marity_test(:p)
 
-    lambda(&method(:assert)).call(true)
-    lambda(&get_block{|a,n| assert(a,n)}).call(true, "marity")
+    get_block{|a,n| assert(a,n)}.call(true, "marity")
   end
 
   def foo
diff --git a/test/ruby/test_lambda.rb b/test/ruby/test_lambda.rb
index 03b501a6c9..75362e2796 100644
--- a/test/ruby/test_lambda.rb
+++ b/test/ruby/test_lambda.rb
@@ -74,6 +74,12 @@ class TestLambdaParameters < Test::Unit::TestCase
     assert_raise(ArgumentError, bug9605) {proc(&plus).call [1,2]}
   end
 
+  def test_warning_for_non_literal_blocks
+    assert_warn(/lambda without a literal block/, '[ruby-core:93482] [Feature #15973]') do
+      lambda(&:symbol)
+    end
+  end
+
   def pass_along(&block)
     lambda(&block)
   end