From 76326044c8cd17348e178ecf1fdc5b9bb91152dc Mon Sep 17 00:00:00 2001
From: Franck Verrot <franck@verrot.fr>
Date: Wed, 12 Nov 2014 05:57:20 +0100
Subject: [PATCH] vm_eval.c: loop now yields a incremented counter

* vm_eval.c (loop_i): make loop yield a counter to
  keep track of the iteration count.
---
 ChangeLog                    |  5 +++++
 test/ruby/test_enumerator.rb |  9 +++++++++
 vm_eval.c                    | 11 +++++++----
 3 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 10036a4..af111f8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Nov 12 05:57:20 2014  Franck Verrot <franck@verrot.fr>
+
+	* vm_eval.c (loop_i): make loop yield a counter to
+	  keep track of the iteration count.
+
 Wed Nov 12 00:26:37 2014  Tanaka Akira  <akr@fsij.org>
 
 	* test/ruby/test_object.rb: Specify an exception class for rescue clause.
diff --git a/test/ruby/test_enumerator.rb b/test/ruby/test_enumerator.rb
index f2a7afa..e86803b 100644
--- a/test/ruby/test_enumerator.rb
+++ b/test/ruby/test_enumerator.rb
@@ -47,6 +47,15 @@ class TestEnumerator < Test::Unit::TestCase
     }
   end
 
+  def test_loop_yield
+    max = 0
+    loop do |i|
+      max = i
+      raise StopIteration if i >= 1
+    end
+    assert_equal 1, max
+  end
+
   def test_nested_iteration
     def (o = Object.new).each
       yield :ok1
diff --git a/vm_eval.c b/vm_eval.c
index a057ece..f376594 100644
--- a/vm_eval.c
+++ b/vm_eval.c
@@ -1007,10 +1007,13 @@ rb_yield_block(VALUE val, VALUE arg, int argc, const VALUE *argv, VALUE blockarg
 static VALUE
 loop_i(void)
 {
-    for (;;) {
-	rb_yield_0(0, 0);
-    }
-    return Qnil;
+  VALUE counter   = INT2FIX(0);
+  VALUE increment = INT2FIX(1);
+  for (;;) {
+    rb_yield_values(1, counter);
+    counter = rb_funcall(counter, '+', 1, increment);
+  }
+  return Qnil;
 }
 
 static VALUE
-- 
1.8.5.2 (Apple Git-48)