Copy hash compare_by_identity setting in more cases

This makes the compare_by_identity setting always copied
for the following methods:

* except
* merge
* reject
* select
* slice
* transform_values

Some of these methods did not copy the setting, or only
copied the setting if the receiver was not empty.

Fixes [Bug #17757]

Co-authored-by: Kenichi Kamiya <kachick1@gmail.com>

1 files changed, 169 insertions, 0 deletions

diff --git a/test/ruby/test_hash.rb b/test/ruby/test_hash.rb
index 7c83d03b6e..028610ea67 100644
--- a/test/ruby/test_hash.rb
+++ b/test/ruby/test_hash.rb
@@ -749,6 +749,33 @@ class TestHash < Test::Unit::TestCase
     assert_not_send([h, :instance_variable_defined?, :@foo])
   end
 
+  def test_reject_on_identhash
+    h = @cls[1=>2,3=>4,5=>6]
+    h.compare_by_identity
+    str1 = +'str'
+    str2 = +'str'
+    h[str1] = 1
+    h[str2] = 2
+    expected = {}.compare_by_identity
+    expected[str1] = 1
+    expected[str2] = 2
+    h2 = h.reject{|k,| k != 'str'}
+    assert_equal(expected, h2)
+    assert_equal(true, h2.compare_by_identity?)
+    h2 = h.reject{true}
+    assert_equal({}.compare_by_identity, h2)
+    assert_equal(true, h2.compare_by_identity?)
+
+    h = @cls[]
+    h.compare_by_identity
+    h2 = h.reject{true}
+    assert_equal({}.compare_by_identity, h2)
+    assert_equal(true, h2.compare_by_identity?)
+    h2 = h.reject{|k,| k != 'str'}
+    assert_equal({}.compare_by_identity, h2)
+    assert_equal(true, h2.compare_by_identity?)
+  end
+
   def test_reject!
     base = @cls[ 1 => 'one', 2 => false, true => 'true', 'cat' => 99 ]
     h1   = @cls[ 1 => 'one', 2 => false, true => 'true' ]
@@ -1076,6 +1103,33 @@ class TestHash < Test::Unit::TestCase
     assert_not_send([h, :instance_variable_defined?, :@foo])
   end
 
+  def test_select_on_identhash
+    h = @cls[1=>2,3=>4,5=>6]
+    h.compare_by_identity
+    str1 = +'str'
+    str2 = +'str'
+    h[str1] = 1
+    h[str2] = 2
+    expected = {}.compare_by_identity
+    expected[str1] = 1
+    expected[str2] = 2
+    h2 = h.select{|k,| k == 'str'}
+    assert_equal(expected, h2)
+    assert_equal(true, h2.compare_by_identity?)
+    h2 = h.select{false}
+    assert_equal({}.compare_by_identity, h2)
+    assert_equal(true, h2.compare_by_identity?)
+
+    h = @cls[]
+    h.compare_by_identity
+    h2 = h.select{false}
+    assert_equal({}.compare_by_identity, h2)
+    assert_equal(true, h2.compare_by_identity?)
+    h2 = h.select{|k,| k == 'str'}
+    assert_equal({}.compare_by_identity, h2)
+    assert_equal(true, h2.compare_by_identity?)
+  end
+
   def test_select!
     h = @cls[1=>2,3=>4,5=>6]
     assert_equal(h, h.select! {|k, v| k + v >= 7 })
@@ -1100,6 +1154,33 @@ class TestHash < Test::Unit::TestCase
     assert_equal({}, {}.slice)
   end
 
+  def test_slice_on_identhash
+    h = @cls[1=>2,3=>4,5=>6]
+    h.compare_by_identity
+    str1 = +'str'
+    str2 = +'str'
+    h[str1] = 1
+    h[str2] = 2
+    sliced = h.slice(str1, str2)
+    expected = {}.compare_by_identity
+    expected[str1] = 1
+    expected[str2] = 2
+    assert_equal(expected, sliced)
+    assert_equal(true, sliced.compare_by_identity?)
+    sliced = h.slice
+    assert_equal({}.compare_by_identity, sliced)
+    assert_equal(true, sliced.compare_by_identity?)
+
+    h = @cls[]
+    h.compare_by_identity
+    sliced= h.slice
+    assert_equal({}.compare_by_identity, sliced)
+    assert_equal(true, sliced.compare_by_identity?)
+    sliced = h.slice(str1, str2)
+    assert_equal({}.compare_by_identity, sliced)
+    assert_equal(true, sliced.compare_by_identity?)
+  end
+
   def test_except
     h = @cls[1=>2,3=>4,5=>6]
     assert_equal({5=>6}, h.except(1, 3))
@@ -1108,6 +1189,30 @@ class TestHash < Test::Unit::TestCase
     assert_equal({}, {}.except)
   end
 
+  def test_except_on_identhash
+    h = @cls[1=>2,3=>4,5=>6]
+    h.compare_by_identity
+    str1 = +'str'
+    str2 = +'str'
+    h[str1] = 1
+    h[str2] = 2
+    excepted = h.except(str1, str2)
+    assert_equal({1=>2,3=>4,5=>6}.compare_by_identity, excepted)
+    assert_equal(true, excepted.compare_by_identity?)
+    excepted = h.except
+    assert_equal(h, excepted)
+    assert_equal(true, excepted.compare_by_identity?)
+
+    h = @cls[]
+    h.compare_by_identity
+    excepted = h.except
+    assert_equal({}.compare_by_identity, excepted)
+    assert_equal(true, excepted.compare_by_identity?)
+    excepted = h.except(str1, str2)
+    assert_equal({}.compare_by_identity, excepted)
+    assert_equal(true, excepted.compare_by_identity?)
+  end
+
   def test_filter
     assert_equal({3=>4,5=>6}, @cls[1=>2,3=>4,5=>6].filter {|k, v| k + v >= 7 })
 
@@ -1267,6 +1372,34 @@ class TestHash < Test::Unit::TestCase
     assert_equal({1=>8, 2=>4, 3=>4, 5=>7}, h1.merge(h2, h3) {|k, v1, v2| k + v1 + v2 })
   end
 
+  def test_merge_on_identhash
+    h = @cls[1=>2,3=>4,5=>6]
+    h.compare_by_identity
+    str1 = +'str'
+    str2 = +'str'
+    h[str1] = 1
+    h[str2] = 2
+    expected = h.dup
+    expected[7] = 8
+    h2 = h.merge(7=>8)
+    assert_equal(expected, h2)
+    assert_equal(true, h2.compare_by_identity?)
+    h2 = h.merge({})
+    assert_equal(h, h2)
+    assert_equal(true, h2.compare_by_identity?)
+
+    h = @cls[]
+    h.compare_by_identity
+    h1 = @cls[7=>8]
+    h1.compare_by_identity
+    h2 = h.merge(7=>8)
+    assert_equal(h1, h2)
+    assert_equal(true, h2.compare_by_identity?)
+    h2 = h.merge({})
+    assert_equal(h, h2)
+    assert_equal(true, h2.compare_by_identity?)
+  end
+
   def test_merge!
     h = @cls[a: 1, b: 2, c: 3]
     assert_raise(FrozenError) do
@@ -1758,6 +1891,24 @@ class TestHash < Test::Unit::TestCase
     assert_equal({A: 1, B: 2, "c" => 3}, x.transform_keys({a: :A, b: :B, d: :D}, &:to_s))
   end
 
+  def test_transform_keys_on_identhash
+    h = @cls[1=>2,3=>4,5=>6]
+    h.compare_by_identity
+    str1 = +'str'
+    str2 = +'str'
+    h[str1] = 1
+    h[str2] = 2
+    h2 = h.transform_keys(&:itself)
+    assert_equal(Hash[h.to_a], h2)
+    assert_equal(false, h2.compare_by_identity?)
+
+    h = @cls[]
+    h.compare_by_identity
+    h2 = h.transform_keys(&:itself)
+    assert_equal({}, h2)
+    assert_equal(false, h2.compare_by_identity?)
+  end
+
   def test_transform_keys_bang
     x = @cls[a: 1, b: 2, c: 3]
     y = x.transform_keys! {|k| :"#{k}!" }
@@ -1808,6 +1959,24 @@ class TestHash < Test::Unit::TestCase
     assert_equal(%w(1.0  2.1  3.2), y.values_at(:a, :b, :c))
   end
 
+  def test_transform_values_on_identhash
+    h = @cls[1=>2,3=>4,5=>6]
+    h.compare_by_identity
+    str1 = +'str'
+    str2 = +'str'
+    h[str1] = 1
+    h[str2] = 2
+    h2 = h.transform_values(&:itself)
+    assert_equal(h, h2)
+    assert_equal(true, h2.compare_by_identity?)
+
+    h = @cls[]
+    h.compare_by_identity
+    h2 = h.transform_values(&:itself)
+    assert_equal({}.compare_by_identity, h2)
+    assert_equal(true, h2.compare_by_identity?)
+  end
+
   def test_transform_values_bang
     x = @cls[a: 1, b: 2, c: 3]
     y = x.transform_values! {|v| v ** 2 }