merge revision(s) cd5e6cc0ea48353c88d921b885b552dc76da255c,bbf54ec334fe2edd7669a944d88d17efde49a412: [Backport #19307]

	Update to ruby/mspec@fef9b81

	---
	 spec/mspec/tool/tag_from_output.rb | 2 +-
	 1 file changed, 1 insertion(+), 1 deletion(-)

	Update to ruby/spec@9d69b95

	---
	 spec/ruby/core/array/keep_if_spec.rb               |   1 +
	 spec/ruby/core/array/pack/c_spec.rb                |  14 +-
	 spec/ruby/core/array/pack/shared/basic.rb          |  40 ++++
	 spec/ruby/core/array/pack/shared/float.rb          |  66 ++++++-
	 spec/ruby/core/array/pack/shared/integer.rb        |  96 +++++++--
	 spec/ruby/core/array/pack/shared/numeric_basic.rb  |  10 +-
	 spec/ruby/core/array/pack/shared/unicode.rb        |  14 +-
	 spec/ruby/core/array/pack/w_spec.rb                |  14 +-
	 spec/ruby/core/array/shared/unshift.rb             |  18 ++
	 spec/ruby/core/array/values_at_spec.rb             |   1 +
	 spec/ruby/core/array/zip_spec.rb                   |   6 +
	 spec/ruby/core/class/subclasses_spec.rb            |  22 +++
	 spec/ruby/core/dir/home_spec.rb                    |  44 +++--
	 spec/ruby/core/dir/mkdir_spec.rb                   |  18 +-
	 spec/ruby/core/enumerable/zip_spec.rb              |   5 +
	 spec/ruby/core/float/comparison_spec.rb            |  35 ++--
	 spec/ruby/core/float/divmod_spec.rb                |   2 +-
	 spec/ruby/core/float/gt_spec.rb                    |  21 ++
	 spec/ruby/core/float/gte_spec.rb                   |  21 ++
	 spec/ruby/core/float/lt_spec.rb                    |  21 ++
	 spec/ruby/core/float/lte_spec.rb                   |  21 ++
	 spec/ruby/core/float/shared/equal.rb               |  21 ++
	 spec/ruby/core/io/gets_spec.rb                     |   4 +
	 spec/ruby/core/io/lineno_spec.rb                   |   9 +-
	 spec/ruby/core/io/new_spec.rb                      |   2 +
	 spec/ruby/core/io/readline_spec.rb                 |   4 +
	 spec/ruby/core/io/readlines_spec.rb                |   4 +
	 spec/ruby/core/io/shared/each.rb                   |   4 +
	 spec/ruby/core/io/shared/new.rb                    |   2 +
	 spec/ruby/core/io/shared/pos.rb                    |   8 +-
	 spec/ruby/core/io/shared/readlines.rb              |   4 +
	 spec/ruby/core/io/sysseek_spec.rb                  |   2 +-
	 spec/ruby/core/kernel/shared/load.rb               |  31 ++-
	 spec/ruby/core/kernel/singleton_class_spec.rb      |   2 +
	 spec/ruby/core/marshal/dump_spec.rb                |  45 ++++-
	 spec/ruby/core/marshal/fixtures/classes.rb         |   4 +
	 spec/ruby/core/matchdata/values_at_spec.rb         |  73 ++++++-
	 spec/ruby/core/module/fixtures/classes.rb          |   1 +
	 spec/ruby/core/module/include_spec.rb              |   4 +-
	 spec/ruby/core/module/prepend_spec.rb              |  12 ++
	 .../ruby/core/objectspace/define_finalizer_spec.rb |  22 +++
	 spec/ruby/core/process/constants_spec.rb           |   1 +
	 spec/ruby/core/process/detach_spec.rb              |  29 +++
	 spec/ruby/core/process/spawn_spec.rb               |  10 +
	 spec/ruby/core/process/times_spec.rb               |   2 +-
	 spec/ruby/core/queue/initialize_spec.rb            |  13 +-
	 spec/ruby/core/refinement/import_methods_spec.rb   |  34 ++++
	 spec/ruby/core/refinement/include_spec.rb          |  27 +++
	 spec/ruby/core/refinement/prepend_spec.rb          |  27 +++
	 spec/ruby/core/regexp/initialize_spec.rb           |   2 +-
	 spec/ruby/core/signal/trap_spec.rb                 |  12 ++
	 spec/ruby/core/string/byteslice_spec.rb            |   6 +
	 spec/ruby/core/string/capitalize_spec.rb           |   4 +
	 spec/ruby/core/string/chars_spec.rb                |   7 +-
	 spec/ruby/core/string/chomp_spec.rb                |   4 +
	 spec/ruby/core/string/chop_spec.rb                 |   4 +
	 spec/ruby/core/string/clone_spec.rb                |   4 +
	 spec/ruby/core/string/delete_prefix_spec.rb        |   4 +
	 spec/ruby/core/string/delete_spec.rb               |   4 +
	 spec/ruby/core/string/delete_suffix_spec.rb        |   4 +
	 spec/ruby/core/string/downcase_spec.rb             |   4 +
	 spec/ruby/core/string/dump_spec.rb                 |  10 +-
	 spec/ruby/core/string/dup_spec.rb                  |   4 +
	 spec/ruby/core/string/lines_spec.rb                |   1 -
	 spec/ruby/core/string/reverse_spec.rb              |   4 +
	 spec/ruby/core/string/scan_spec.rb                 |   6 +
	 spec/ruby/core/string/scrub_spec.rb                |  10 +
	 spec/ruby/core/string/shared/each_line.rb          |   6 +
	 spec/ruby/core/string/shared/partition.rb          |  15 ++
	 spec/ruby/core/string/shared/slice.rb              |  13 +-
	 spec/ruby/core/string/shared/strip.rb              |   4 +
	 spec/ruby/core/string/shared/succ.rb               |   4 +
	 spec/ruby/core/string/split_spec.rb                |  17 +-
	 spec/ruby/core/string/squeeze_spec.rb              |   5 +
	 spec/ruby/core/string/swapcase_spec.rb             |   4 +
	 spec/ruby/core/string/undump_spec.rb               |   2 +-
	 spec/ruby/core/string/unpack/b_spec.rb             |  28 ++-
	 spec/ruby/core/string/unpack/c_spec.rb             |  14 +-
	 spec/ruby/core/string/unpack/h_spec.rb             |  28 ++-
	 spec/ruby/core/string/unpack/shared/basic.rb       |  28 ---
	 spec/ruby/core/string/unpack/shared/float.rb       |  60 +++++-
	 spec/ruby/core/string/unpack/shared/integer.rb     |  88 +++++++--
	 spec/ruby/core/string/unpack/shared/unicode.rb     |  14 +-
	 spec/ruby/core/string/unpack/w_spec.rb             |  14 +-
	 spec/ruby/core/string/unpack1_spec.rb              |  12 +-
	 spec/ruby/core/string/unpack_spec.rb               |  34 ++++
	 spec/ruby/core/string/upcase_spec.rb               |   4 +
	 spec/ruby/core/string/valid_encoding/utf_8_spec.rb | 214 +++++++++++++++++++++
	 spec/ruby/core/struct/values_at_spec.rb            |  55 +++++-
	 spec/ruby/core/symbol/shared/id2name.rb            |   7 +
	 spec/ruby/core/time/at_spec.rb                     |  16 ++
	 spec/ruby/core/time/localtime_spec.rb              |  16 +-
	 spec/ruby/core/time/new_spec.rb                    |  94 +++++++--
	 spec/ruby/core/time/shared/gmtime.rb               |   4 +-
	 spec/ruby/core/time/shared/time_params.rb          |  11 +-
	 spec/ruby/core/time/strftime_spec.rb               |  40 +++-
	 spec/ruby/core/time/utc_spec.rb                    |  41 +++-
	 spec/ruby/core/time/zone_spec.rb                   |  20 +-
	 spec/ruby/core/tracepoint/inspect_spec.rb          |   9 +
	 spec/ruby/fixtures/code/load_wrap_fixture.rb       |  12 ++
	 spec/ruby/fixtures/code/wrap_fixture.rb            |   9 -
	 spec/ruby/language/case_spec.rb                    |   4 +-
	 .../ruby/language/regexp/character_classes_spec.rb |   5 +
	 spec/ruby/library/coverage/running_spec.rb         |  20 ++
	 spec/ruby/library/date/civil_spec.rb               |   7 +-
	 spec/ruby/library/objectspace/fixtures/trace.rb    |   5 +
	 spec/ruby/library/objectspace/trace_spec.rb        |  15 ++
	 spec/ruby/library/openssl/x509/name/verify_spec.rb |   4 +-
	 spec/ruby/library/stringio/initialize_spec.rb      |  85 ++++++++
	 spec/ruby/library/stringio/new_spec.rb             |   8 +
	 spec/ruby/library/stringio/shared/write.rb         |  22 +++
	 spec/ruby/optional/capi/ext/io_spec.c              |  43 +++++
	 spec/ruby/optional/capi/io_spec.rb                 |  15 ++
	 spec/ruby/shared/rational/Rational.rb              |  48 ++---
	 114 files changed, 1963 insertions(+), 245 deletions(-)
	 create mode 100644 spec/ruby/core/marshal/fixtures/classes.rb
	 create mode 100644 spec/ruby/core/refinement/import_methods_spec.rb
	 create mode 100644 spec/ruby/core/refinement/include_spec.rb
	 create mode 100644 spec/ruby/core/refinement/prepend_spec.rb
	 create mode 100644 spec/ruby/core/string/unpack_spec.rb
	 create mode 100644 spec/ruby/core/string/valid_encoding/utf_8_spec.rb
	 create mode 100644 spec/ruby/fixtures/code/load_wrap_fixture.rb
	 delete mode 100644 spec/ruby/fixtures/code/wrap_fixture.rb
	 create mode 100644 spec/ruby/library/coverage/running_spec.rb
	 create mode 100644 spec/ruby/library/objectspace/fixtures/trace.rb
	 create mode 100644 spec/ruby/library/objectspace/trace_spec.rb
	 create mode 100644 spec/ruby/library/stringio/new_spec.rb

8 files changed, 208 insertions, 66 deletions

diff --git a/spec/ruby/core/string/unpack/b_spec.rb b/spec/ruby/core/string/unpack/b_spec.rb
index fcabc99731..2cf5ebad34 100644
--- a/spec/ruby/core/string/unpack/b_spec.rb
+++ b/spec/ruby/core/string/unpack/b_spec.rb
@@ -86,8 +86,18 @@ describe "String#unpack with format 'B'" do
     ].should be_computed_by(:unpack, "BBB")
   end
 
-  it "ignores NULL bytes between directives" do
-    "\x80\x00".unpack("B\x00B").should == ["1", "0"]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      "\x80\x00".unpack("B\x00B").should == ["1", "0"]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "\x80\x00".unpack("B\x00B")
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
@@ -182,8 +192,18 @@ describe "String#unpack with format 'b'" do
     ].should be_computed_by(:unpack, "bbb")
   end
 
-  it "ignores NULL bytes between directives" do
-    "\x01\x00".unpack("b\x00b").should == ["1", "0"]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      "\x01\x00".unpack("b\x00b").should == ["1", "0"]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "\x01\x00".unpack("b\x00b")
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
diff --git a/spec/ruby/core/string/unpack/c_spec.rb b/spec/ruby/core/string/unpack/c_spec.rb
index ed8caa4895..dbcbacc74d 100644
--- a/spec/ruby/core/string/unpack/c_spec.rb
+++ b/spec/ruby/core/string/unpack/c_spec.rb
@@ -35,8 +35,18 @@ describe :string_unpack_8bit, shared: true do
     ].should be_computed_by(:unpack, unpack_format(3))
   end
 
-  it "ignores NULL bytes between directives" do
-    "abc".unpack(unpack_format("\000", 2)).should == [97, 98]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      "abc".unpack(unpack_format("\000", 2)).should == [97, 98]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "abc".unpack(unpack_format("\000", 2))
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
diff --git a/spec/ruby/core/string/unpack/h_spec.rb b/spec/ruby/core/string/unpack/h_spec.rb
index f2f5dcf396..ee08d20926 100644
--- a/spec/ruby/core/string/unpack/h_spec.rb
+++ b/spec/ruby/core/string/unpack/h_spec.rb
@@ -56,8 +56,18 @@ describe "String#unpack with format 'H'" do
     ].should be_computed_by(:unpack, "HHH")
   end
 
-  it "ignores NULL bytes between directives" do
-    "\x01\x10".unpack("H\x00H").should == ["0", "1"]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      "\x01\x10".unpack("H\x00H").should == ["0", "1"]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "\x01\x10".unpack("H\x00H")
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
@@ -121,8 +131,18 @@ describe "String#unpack with format 'h'" do
     ].should be_computed_by(:unpack, "hhh")
   end
 
-  it "ignores NULL bytes between directives" do
-    "\x01\x10".unpack("h\x00h").should == ["1", "0"]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      "\x01\x10".unpack("h\x00h").should == ["1", "0"]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "\x01\x10".unpack("h\x00h")
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
diff --git a/spec/ruby/core/string/unpack/shared/basic.rb b/spec/ruby/core/string/unpack/shared/basic.rb
index f636f4689f..bb5302edc5 100644
--- a/spec/ruby/core/string/unpack/shared/basic.rb
+++ b/spec/ruby/core/string/unpack/shared/basic.rb
@@ -8,20 +8,6 @@ describe :string_unpack_basic, shared: true do
     d.should_receive(:to_str).and_return("a"+unpack_format)
     "abc".unpack(d).should be_an_instance_of(Array)
   end
-
-  it "raises a TypeError when passed nil" do
-    -> { "abc".unpack(nil) }.should raise_error(TypeError)
-  end
-
-  it "raises a TypeError when passed an Integer" do
-    -> { "abc".unpack(1) }.should raise_error(TypeError)
-  end
-
-  ruby_version_is "3.1" do
-    it "starts unpacking from the given offset" do
-      "abc".unpack("CC", offset: 1).should == [98, 99]
-    end
-  end
 end
 
 describe :string_unpack_no_platform, shared: true do
@@ -32,18 +18,4 @@ describe :string_unpack_no_platform, shared: true do
   it "raises an ArgumentError when the format modifier is '!'" do
     -> { "abcdefgh".unpack(unpack_format("!")) }.should raise_error(ArgumentError)
   end
-
-  ruby_version_is "3.1" do
-    it "raises an ArgumentError when the offset is negative" do
-      -> { "a".unpack("C", offset: -1) }.should raise_error(ArgumentError)
-    end
-
-    it "returns nil if the offset is at the end of the string" do
-      "a".unpack("C", offset: 1).should == [nil]
-    end
-
-    it "raises an ArgumentError when the offset is larget than the string" do
-      -> { "a".unpack("C", offset: 2) }.should raise_error(ArgumentError)
-    end
-  end
 end
diff --git a/spec/ruby/core/string/unpack/shared/float.rb b/spec/ruby/core/string/unpack/shared/float.rb
index 99bd8a3401..ccddf94f99 100644
--- a/spec/ruby/core/string/unpack/shared/float.rb
+++ b/spec/ruby/core/string/unpack/shared/float.rb
@@ -56,9 +56,19 @@ describe :string_unpack_float_le, shared: true do
     [nan_value].pack(unpack_format).unpack(unpack_format).first.nan?.should be_true
   end
 
-  it "ignores NULL bytes between directives" do
-    array = "\x9a\x999@33\xb3?".unpack(unpack_format("\000", 2))
-    array.should == [2.9000000953674316, 1.399999976158142]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      array = "\x9a\x999@33\xb3?".unpack(unpack_format("\000", 2))
+      array.should == [2.9000000953674316, 1.399999976158142]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "\x9a\x999@33\xb3?".unpack(unpack_format("\000", 2))
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
@@ -123,9 +133,19 @@ describe :string_unpack_float_be, shared: true do
     [nan_value].pack(unpack_format).unpack(unpack_format).first.nan?.should be_true
   end
 
-  it "ignores NULL bytes between directives" do
-    array = "@9\x99\x9a?\xb333".unpack(unpack_format("\000", 2))
-    array.should == [2.9000000953674316, 1.399999976158142]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      array = "@9\x99\x9a?\xb333".unpack(unpack_format("\000", 2))
+      array.should == [2.9000000953674316, 1.399999976158142]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "@9\x99\x9a?\xb333".unpack(unpack_format("\000", 2))
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
@@ -193,8 +213,18 @@ describe :string_unpack_double_le, shared: true do
     [nan_value].pack(unpack_format).unpack(unpack_format).first.nan?.should be_true
   end
 
-  it "ignores NULL bytes between directives" do
-    "333333\x07@ffffff\xf6?".unpack(unpack_format("\000", 2)).should == [2.9, 1.4]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      "333333\x07@ffffff\xf6?".unpack(unpack_format("\000", 2)).should == [2.9, 1.4]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "333333\x07@ffffff\xf6?".unpack(unpack_format("\000", 2))
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
@@ -261,8 +291,18 @@ describe :string_unpack_double_be, shared: true do
     [nan_value].pack(unpack_format).unpack(unpack_format).first.nan?.should be_true
   end
 
-  it "ignores NULL bytes between directives" do
-    "@\x07333333?\xf6ffffff".unpack(unpack_format("\000", 2)).should == [2.9, 1.4]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      "@\x07333333?\xf6ffffff".unpack(unpack_format("\000", 2)).should == [2.9, 1.4]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "@\x07333333?\xf6ffffff".unpack(unpack_format("\000", 2))
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
diff --git a/spec/ruby/core/string/unpack/shared/integer.rb b/spec/ruby/core/string/unpack/shared/integer.rb
index cbaa743683..ba4f149dad 100644
--- a/spec/ruby/core/string/unpack/shared/integer.rb
+++ b/spec/ruby/core/string/unpack/shared/integer.rb
@@ -32,8 +32,18 @@ describe :string_unpack_16bit_le, shared: true do
     ].should be_computed_by(:unpack, unpack_format(3))
   end
 
-  it "ignores NULL bytes between directives" do
-    "abcd".unpack(unpack_format("\000", 2)).should == [25185, 25699]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      "abcd".unpack(unpack_format("\000", 2)).should == [25185, 25699]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "abcd".unpack(unpack_format("\000", 2))
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
@@ -85,8 +95,18 @@ describe :string_unpack_16bit_be, shared: true do
     ].should be_computed_by(:unpack, unpack_format(3))
   end
 
-  it "ignores NULL bytes between directives" do
-    "badc".unpack(unpack_format("\000", 2)).should == [25185, 25699]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      "badc".unpack(unpack_format("\000", 2)).should == [25185, 25699]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "badc".unpack(unpack_format("\000", 2))
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
@@ -139,8 +159,18 @@ describe :string_unpack_32bit_le, shared: true do
     ].should be_computed_by(:unpack, unpack_format(3))
   end
 
-  it "ignores NULL bytes between directives" do
-    "abcdefgh".unpack(unpack_format("\000", 2)).should == [1684234849, 1751606885]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      "abcdefgh".unpack(unpack_format("\000", 2)).should == [1684234849, 1751606885]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "abcdefgh".unpack(unpack_format("\000", 2))
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
@@ -193,8 +223,18 @@ describe :string_unpack_32bit_be, shared: true do
     ].should be_computed_by(:unpack, unpack_format(3))
   end
 
-  it "ignores NULL bytes between directives" do
-    "dcbahgfe".unpack(unpack_format("\000", 2)).should == [1684234849, 1751606885]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      "dcbahgfe".unpack(unpack_format("\000", 2)).should == [1684234849, 1751606885]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "dcbahgfe".unpack(unpack_format("\000", 2))
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
@@ -243,9 +283,19 @@ describe :string_unpack_64bit_le, shared: true do
     "abc".unpack(unpack_format('*')).should == []
   end
 
-  it "ignores NULL bytes between directives" do
-    array = "abcdefghabghefcd".unpack(unpack_format("\000", 2))
-    array.should == [7523094288207667809, 7233738012216484449]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      array = "abcdefghabghefcd".unpack(unpack_format("\000", 2))
+      array.should == [7523094288207667809, 7233738012216484449]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "badc".unpack(unpack_format("\000", 2))
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
@@ -305,9 +355,19 @@ describe :string_unpack_64bit_be, shared: true do
     "abc".unpack(unpack_format('*')).should == []
   end
 
-  it "ignores NULL bytes between directives" do
-    array = "hgfedcbadcfehgba".unpack(unpack_format("\000", 2))
-    array.should == [7523094288207667809, 7233738012216484449]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      array = "hgfedcbadcfehgba".unpack(unpack_format("\000", 2))
+      array.should == [7523094288207667809, 7233738012216484449]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "hgfedcbadcfehgba".unpack(unpack_format("\000", 2))
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
diff --git a/spec/ruby/core/string/unpack/shared/unicode.rb b/spec/ruby/core/string/unpack/shared/unicode.rb
index a2b4e142b2..ce1f29fe87 100644
--- a/spec/ruby/core/string/unpack/shared/unicode.rb
+++ b/spec/ruby/core/string/unpack/shared/unicode.rb
@@ -50,8 +50,18 @@ describe :string_unpack_unicode, shared: true do
     "\xc2\x80".unpack("UUUU").should == [0x80]
   end
 
-  it "ignores NULL bytes between directives" do
-    "\x01\x02".unpack("U\x00U").should == [1, 2]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      "\x01\x02".unpack("U\x00U").should == [1, 2]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "\x01\x02".unpack("U\x00U")
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do
diff --git a/spec/ruby/core/string/unpack/w_spec.rb b/spec/ruby/core/string/unpack/w_spec.rb
index 011c75f5c4..b213b32921 100644
--- a/spec/ruby/core/string/unpack/w_spec.rb
+++ b/spec/ruby/core/string/unpack/w_spec.rb
@@ -15,8 +15,18 @@ describe "String#unpack with directive 'w'" do
     ].should be_computed_by(:unpack, "w")
   end
 
-  it "ignores NULL bytes between directives" do
-    "\x01\x02\x03".unpack("w\x00w").should == [1, 2]
+  ruby_version_is ""..."3.3" do
+    it "ignores NULL bytes between directives" do
+      "\x01\x02\x03".unpack("w\x00w").should == [1, 2]
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raise ArgumentError for NULL bytes between directives" do
+      -> {
+        "\x01\x02\x03".unpack("w\x00w")
+      }.should raise_error(ArgumentError, /unknown unpack directive/)
+    end
   end
 
   it "ignores spaces between directives" do