From 89ca842dcce7f05942e2d7be3edc404c9556cafd Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Fri, 2 Oct 2020 10:57:07 +0900
Subject: [PATCH] Ensure that the comparison succeeded [Bug #17205]

---
 numeric.c               |  4 +++-
 test/ruby/test_array.rb | 21 +++++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/numeric.c b/numeric.c
index 6d4eb86b1a..a767c12bf8 100644
--- a/numeric.c
+++ b/numeric.c
@@ -1518,7 +1518,9 @@ flo_cmp(VALUE x, VALUE y)
 MJIT_FUNC_EXPORTED int
 rb_float_cmp(VALUE x, VALUE y)
 {
-    return NUM2INT(flo_cmp(x, y));
+    VALUE c = flo_cmp(x, y);
+    if (NIL_P(c)) rb_cmperr(x, y);
+    return NUM2INT(c);
 }
 
 /*
diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb
index 64bcf9f1aa..5d1785220e 100644
--- a/test/ruby/test_array.rb
+++ b/test/ruby/test_array.rb
@@ -1648,6 +1648,13 @@ class TestArray < Test::Unit::TestCase
     TEST
   end
 
+  def test_sort_uncomparable
+    assert_raise(ArgumentError) {[1, Float::NAN].sort}
+    assert_raise(ArgumentError) {[1.0, Float::NAN].sort}
+    assert_raise(ArgumentError) {[Float::NAN, 1].sort}
+    assert_raise(ArgumentError) {[Float::NAN, 1.0].sort}
+  end
+
   def test_to_a
     a = @cls[ 1, 2, 3 ]
     a_id = a.__id__
@@ -1768,6 +1775,13 @@ class TestArray < Test::Unit::TestCase
     assert_same(obj, [obj, 1.0].min)
   end
 
+  def test_min_uncomparable
+    assert_raise(ArgumentError) {[1, Float::NAN].min}
+    assert_raise(ArgumentError) {[1.0, Float::NAN].min}
+    assert_raise(ArgumentError) {[Float::NAN, 1].min}
+    assert_raise(ArgumentError) {[Float::NAN, 1.0].min}
+  end
+
   def test_max
     assert_equal(1, [1].max)
     assert_equal(3, [1, 2, 3, 1, 2].max)
@@ -1791,6 +1805,13 @@ class TestArray < Test::Unit::TestCase
     assert_same(obj, [obj, 1.0].max)
   end
 
+  def test_max_uncomparable
+    assert_raise(ArgumentError) {[1, Float::NAN].max}
+    assert_raise(ArgumentError) {[1.0, Float::NAN].max}
+    assert_raise(ArgumentError) {[Float::NAN, 1].max}
+    assert_raise(ArgumentError) {[Float::NAN, 1.0].max}
+  end
+
   def test_minmax
     assert_equal([3, 3], [3].minmax)
     assert_equal([1, 3], [1, 2, 3, 1, 2].minmax)