From fa674cf7230e40bc96625ee97a6057e48bb20f0f Mon Sep 17 00:00:00 2001
From: Jean Boussier <jean.boussier@gmail.com>
Date: Mon, 15 Nov 2021 11:37:40 +0100
Subject: [PATCH] [ruby/date] `Date._<format>(nil)` should return an empty Hash

Fix: https://github.com/ruby/date/issues/39

This is how versions previous to 3.2.1 behaved and Active Support
currently rely on this behavior.

https://github.com/rails/rails/blob/90357af08048ef5076730505f6e7b14a81f33d0c/activesupport/lib/active_support/values/time_zone.rb#L383-L384

Any Rails application upgrading to date `3.2.1` might run into unexpected errors.

https://github.com/ruby/date/commit/8f2d7a0c7e
---
 ext/date/date_core.c         |  2 ++
 test/date/test_date_parse.rb | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/ext/date/date_core.c b/ext/date/date_core.c
index 177ea0f..516640b 100644
--- a/ext/date/date_core.c
+++ b/ext/date/date_core.c
@@ -4304,6 +4304,8 @@ get_limit(VALUE opt)
 static void
 check_limit(VALUE str, VALUE opt)
 {
+    if (NIL_P(str)) return;
+
     StringValue(str);
     size_t slen = RSTRING_LEN(str);
     size_t limit = get_limit(opt);
diff --git a/test/date/test_date_parse.rb b/test/date/test_date_parse.rb
index f9b160e..dfc018b 100644
--- a/test/date/test_date_parse.rb
+++ b/test/date/test_date_parse.rb
@@ -824,6 +824,9 @@ class TestDateParse < Test::Unit::TestCase
 
     h = Date._iso8601('')
     assert_equal({}, h)
+
+    h = Date._iso8601(nil)
+    assert_equal({}, h)
   end
 
   def test__rfc3339
@@ -839,6 +842,9 @@ class TestDateParse < Test::Unit::TestCase
 
     h = Date._rfc3339('')
     assert_equal({}, h)
+
+    h = Date._rfc3339(nil)
+    assert_equal({}, h)
   end
 
   def test__xmlschema
@@ -921,6 +927,9 @@ class TestDateParse < Test::Unit::TestCase
 
     h = Date._xmlschema('')
     assert_equal({}, h)
+
+    h = Date._xmlschema(nil)
+    assert_equal({}, h)
   end
 
   def test__rfc2822
@@ -953,6 +962,9 @@ class TestDateParse < Test::Unit::TestCase
 
     h = Date._rfc2822('')
     assert_equal({}, h)
+
+    h = Date._rfc2822(nil)
+    assert_equal({}, h)
   end
 
   def test__httpdate
@@ -973,6 +985,9 @@ class TestDateParse < Test::Unit::TestCase
 
     h = Date._httpdate('')
     assert_equal({}, h)
+
+    h = Date._httpdate(nil)
+    assert_equal({}, h)
   end
 
   def test__jisx0301
@@ -1001,6 +1016,9 @@ class TestDateParse < Test::Unit::TestCase
 
     h = Date._jisx0301('')
     assert_equal({}, h)
+
+    h = Date._jisx0301(nil)
+    assert_equal({}, h)
   end
 
   def test_iso8601
-- 
2.33.0