Raise TypeError for endless non-numeric range include?

Beginless ranges previously raised TypeError for this case,
except for string ranges, which had unexpected behavior:

  ('a'..'z').include?('ww') # false
  (..'z').include?('ww') # previously true, now TypeError

Use of include? with endless ranges could previously result
in an infinite loop.

This splits off a range_string_cover_internal function from
range_include_internal.

Fixes [Bug #18580]

1 files changed, 6 insertions, 5 deletions

diff --git a/test/ruby/test_range.rb b/test/ruby/test_range.rb
index 2c07cef96e..bb5ef6df8f 100644
--- a/test/ruby/test_range.rb
+++ b/test/ruby/test_range.rb
@@ -546,7 +546,7 @@ class TestRange < Test::Unit::TestCase
     assert_not_operator('A'..'Z', :===, 'ana')
     assert_operator('A'.., :===, 'ANA')
     assert_operator(..'Z', :===, 'ANA')
-    assert_operator(nil..nil, :===, 'ANA')
+    assert_raise(TypeError) {(nil..nil) === 'ANA'}
   end
 
   def test_eqq_time
@@ -599,13 +599,14 @@ class TestRange < Test::Unit::TestCase
     assert_include("a"..."z", "y")
     assert_not_include("a"..."z", "z")
     assert_not_include("a".."z", "cc")
-    assert_include("a".., "c")
-    assert_not_include("a".., "5")
+    assert_raise(TypeError) {("a"..).include?("c")}
+    assert_raise(TypeError) {("a"..).include?("5")}
+
     assert_include(0...10, 5)
     assert_include(5..., 10)
     assert_not_include(5..., 0)
-    assert_include(.."z", "z")
-    assert_not_include(..."z", "z")
+    assert_raise(TypeError) {(.."z").include?("z")}
+    assert_raise(TypeError) {(..."z").include?("z")}
     assert_include(..10, 10)
     assert_not_include(...10, 10)
   end