Merge pull request #1055 from alco/record-rewriter-fix

Add missing trivial clauses to record rewriter

Author: José Valim

lib/elixir/lib/kernel/record_rewriter.ex

@@ -350,6 +350,10 @@ defmodule Kernel.RecordRewriter do
     vars
   end
 
+  defp join_dict([]) do
+    []
+  end
+
   defp join_dict([{ _, dict, _ }|t]) do
     join_dict(t, dict)
   end
@@ -374,6 +378,10 @@ defmodule Kernel.RecordRewriter do
     other
   end
 
+  defp join_result([]) do
+    []
+  end
+
   defp join_result([{ _, _, res }|t]) do
     join_result(t, res)
   end

lib/elixir/test/elixir/kernel/record_rewriter_test.exs

@@ -172,6 +172,11 @@ defmodule Kernel.RecordRewriterTest do
     assert optimize_clause(clause) == { clause, [x: Range], { Range, [nil, { :foo, nil }, nil] } }
   end
 
+  test "empty receive" do
+    clause = clause(fn -> receive do end end)
+    assert optimize_clause(clause) == { clause, [], [] }
+  end
+
   test "inside receive" do
     clause = clause(fn -> receive do x = Macro.Env[] -> x; Macro.Env[] = x -> x end end)
     assert optimize_clause(clause) == { clause, [x: Macro.Env], { Macro.Env, nil } }