From ab51b021856ccafb1024fae493a405d590142a07 Mon Sep 17 00:00:00 2001
From: yui-knk <spiketeika@gmail.com>
Date: Wed, 11 Nov 2015 16:52:48 +0900
Subject: [PATCH] Not raise `KeyError` when an arg hash of `sprintf` has key
 whose value is `nil`

---
 sprintf.c                 | 2 +-
 test/ruby/test_sprintf.rb | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/sprintf.c b/sprintf.c
index 5c0f940..10a8aed 100644
--- a/sprintf.c
+++ b/sprintf.c
@@ -609,7 +609,7 @@ rb_str_format(int argc, const VALUE *argv, VALUE fmt)
 				     len - 2 /* without parenthesis */,
 				     enc);
 		nextvalue = rb_hash_aref(hash, sym);
-		if (NIL_P(nextvalue) && !FL_TEST(hash, HASH_PROC_DEFAULT)) {
+                if (NIL_P(nextvalue) && (rb_hash_has_key(hash, sym) == Qfalse) && !FL_TEST(hash, HASH_PROC_DEFAULT)) {
 		    rb_enc_raise(enc, rb_eKeyError, "key%.*s not found", len, start);
 		}
 		if (term == '}') goto format_s;
diff --git a/test/ruby/test_sprintf.rb b/test/ruby/test_sprintf.rb
index 97eb480..8af94a8 100644
--- a/test/ruby/test_sprintf.rb
+++ b/test/ruby/test_sprintf.rb
@@ -415,4 +415,9 @@ class TestSprintf < Test::Unit::TestCase
     assert_equal("hello world", "hello %{location}" % h)
     assert_equal("hello world", "hello %<location>s" % h)
   end
+
+  def test_named_with_nil
+    h = { key: nil, key2: "key2_val" }
+    assert_equal("key is , key2 is key2_val", "key is %{key}, key2 is %{key2}" % h)
+  end
 end
-- 
2.3.2 (Apple Git-55)