Merge branch 'block_args_for_stabby_lambdas'

lib/ruby_parser/bm_sexp.rb

@@ -371,7 +371,11 @@ class Sexp
   #       s(:call, nil, :p, s(:arglist, s(:lvar, :y))))
   def block_args
     expect :iter, :call_with_block
-    self[2]
+    if self[2] == 0 # ?! See https://github.com/presidentbeef/brakeman/issues/331
+      return Sexp.new(:args)
+    else
+      self[2]
+    end
   end
 
   def first_param

test/tests/test_sexp.rb

@@ -87,6 +87,15 @@ class SexpTests < Test::Unit::TestCase
     assert_equal s(:call, nil, :blah, s(:lvar, :z)), block
   end
 
+  def test_stabby_lambda_no_args
+    exp = parse "->{ hi }"
+    args = exp.block_args
+
+    assert_equal s(:call, nil, :lambda), exp.block_call
+    assert_equal s(:args), exp.block_args
+    assert_equal s(:call, nil, :hi), exp.block
+  end
+
   def test_or
     exp = parse '1 or 2'