4 files changed, 55 insertions, 17 deletions
diff --git a/spec/ruby/core/string/unpack/shared/basic.rb b/spec/ruby/core/string/unpack/shared/basic.rb
index bb5302edc5..734630bda0 100644
--- a/spec/ruby/core/string/unpack/shared/basic.rb
+++ b/spec/ruby/core/string/unpack/shared/basic.rb
@@ -8,6 +8,22 @@ 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
+
+  ruby_version_is ""..."3.3" do
+    it "warns about using an unknown directive" do
+      -> { "abcdefgh".unpack("a R" + unpack_format) }.should complain(/unknown unpack directive 'R' in 'a R#{unpack_format}'/)
+      -> { "abcdefgh".unpack("a 0" + unpack_format) }.should complain(/unknown unpack directive '0' in 'a 0#{unpack_format}'/)
+      -> { "abcdefgh".unpack("a :" + unpack_format) }.should complain(/unknown unpack directive ':' in 'a :#{unpack_format}'/)
+    end
+  end
+
+  ruby_version_is "3.3" do
+    it "raises ArgumentError when a directive is unknown" do
+      -> { "abcdefgh".unpack("a K" + unpack_format) }.should raise_error(ArgumentError, "unknown unpack directive 'K' in 'a K#{unpack_format}'")
+      -> { "abcdefgh".unpack("a 0" + unpack_format) }.should raise_error(ArgumentError, "unknown unpack directive '0' in 'a 0#{unpack_format}'")
+      -> { "abcdefgh".unpack("a :" + unpack_format) }.should raise_error(ArgumentError, "unknown unpack directive ':' in 'a :#{unpack_format}'")
+    end
+  end
 end
 
 describe :string_unpack_no_platform, shared: true do
diff --git a/spec/ruby/core/string/unpack/shared/float.rb b/spec/ruby/core/string/unpack/shared/float.rb
index ccddf94f99..b31c2c8bdc 100644
--- a/spec/ruby/core/string/unpack/shared/float.rb
+++ b/spec/ruby/core/string/unpack/shared/float.rb
@@ -1,4 +1,4 @@
-# -*- encoding: binary -*-
+# encoding: binary
 
 describe :string_unpack_float_le, shared: true do
   it "decodes one float for a single format character" do
@@ -58,8 +58,10 @@ describe :string_unpack_float_le, shared: true do
 
   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]
+      suppress_warning do
+        array = "\x9a\x999@33\xb3?".unpack(unpack_format("\000", 2))
+        array.should == [2.9000000953674316, 1.399999976158142]
+      end
     end
   end
 
@@ -135,8 +137,10 @@ describe :string_unpack_float_be, shared: true do
 
   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]
+      suppress_warning do
+        array = "@9\x99\x9a?\xb333".unpack(unpack_format("\000", 2))
+        array.should == [2.9000000953674316, 1.399999976158142]
+      end
     end
   end
 
@@ -215,7 +219,9 @@ describe :string_unpack_double_le, shared: true do
 
   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]
+      suppress_warning do
+        "333333\x07@ffffff\xf6?".unpack(unpack_format("\000", 2)).should == [2.9, 1.4]
+      end
     end
   end
 
@@ -293,7 +299,9 @@ describe :string_unpack_double_be, shared: true do
 
   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]
+      suppress_warning do
+        "@\x07333333?\xf6ffffff".unpack(unpack_format("\000", 2)).should == [2.9, 1.4]
+      end
     end
   end
 
diff --git a/spec/ruby/core/string/unpack/shared/integer.rb b/spec/ruby/core/string/unpack/shared/integer.rb
index ba4f149dad..d3934753ba 100644
--- a/spec/ruby/core/string/unpack/shared/integer.rb
+++ b/spec/ruby/core/string/unpack/shared/integer.rb
@@ -1,4 +1,4 @@
-# -*- encoding: binary -*-
+# encoding: binary
 
 describe :string_unpack_16bit_le, shared: true do
   it "decodes one short for a single format character" do
@@ -34,7 +34,9 @@ describe :string_unpack_16bit_le, shared: true do
 
   ruby_version_is ""..."3.3" do
     it "ignores NULL bytes between directives" do
-      "abcd".unpack(unpack_format("\000", 2)).should == [25185, 25699]
+      suppress_warning do
+        "abcd".unpack(unpack_format("\000", 2)).should == [25185, 25699]
+      end
     end
   end
 
@@ -97,7 +99,9 @@ describe :string_unpack_16bit_be, shared: true do
 
   ruby_version_is ""..."3.3" do
     it "ignores NULL bytes between directives" do
-      "badc".unpack(unpack_format("\000", 2)).should == [25185, 25699]
+      suppress_warning do
+        "badc".unpack(unpack_format("\000", 2)).should == [25185, 25699]
+      end
     end
   end
 
@@ -161,7 +165,9 @@ describe :string_unpack_32bit_le, shared: true do
 
   ruby_version_is ""..."3.3" do
     it "ignores NULL bytes between directives" do
-      "abcdefgh".unpack(unpack_format("\000", 2)).should == [1684234849, 1751606885]
+      suppress_warning do
+        "abcdefgh".unpack(unpack_format("\000", 2)).should == [1684234849, 1751606885]
+      end
     end
   end
 
@@ -225,7 +231,9 @@ describe :string_unpack_32bit_be, shared: true do
 
   ruby_version_is ""..."3.3" do
     it "ignores NULL bytes between directives" do
-      "dcbahgfe".unpack(unpack_format("\000", 2)).should == [1684234849, 1751606885]
+      suppress_warning do
+        "dcbahgfe".unpack(unpack_format("\000", 2)).should == [1684234849, 1751606885]
+      end
     end
   end
 
@@ -285,8 +293,10 @@ describe :string_unpack_64bit_le, shared: true do
 
   ruby_version_is ""..."3.3" do
     it "ignores NULL bytes between directives" do
-      array = "abcdefghabghefcd".unpack(unpack_format("\000", 2))
-      array.should == [7523094288207667809, 7233738012216484449]
+      suppress_warning do
+        array = "abcdefghabghefcd".unpack(unpack_format("\000", 2))
+        array.should == [7523094288207667809, 7233738012216484449]
+      end
     end
   end
 
@@ -357,8 +367,10 @@ describe :string_unpack_64bit_be, shared: true do
 
   ruby_version_is ""..."3.3" do
     it "ignores NULL bytes between directives" do
-      array = "hgfedcbadcfehgba".unpack(unpack_format("\000", 2))
-      array.should == [7523094288207667809, 7233738012216484449]
+      suppress_warning do
+        array = "hgfedcbadcfehgba".unpack(unpack_format("\000", 2))
+        array.should == [7523094288207667809, 7233738012216484449]
+      end
     end
   end
 
diff --git a/spec/ruby/core/string/unpack/shared/unicode.rb b/spec/ruby/core/string/unpack/shared/unicode.rb
index ce1f29fe87..9fe07f53ae 100644
--- a/spec/ruby/core/string/unpack/shared/unicode.rb
+++ b/spec/ruby/core/string/unpack/shared/unicode.rb
@@ -52,7 +52,9 @@ describe :string_unpack_unicode, shared: true do
 
   ruby_version_is ""..."3.3" do
     it "ignores NULL bytes between directives" do
-      "\x01\x02".unpack("U\x00U").should == [1, 2]
+      suppress_warning do
+        "\x01\x02".unpack("U\x00U").should == [1, 2]
+      end
     end
   end