3 files changed, 25 insertions, 28 deletions
diff --git a/spec/ruby/shared/string/end_with.rb b/spec/ruby/shared/string/end_with.rb
index 5f2a011235..94a7f97513 100644
--- a/spec/ruby/shared/string/end_with.rb
+++ b/spec/ruby/shared/string/end_with.rb
@@ -38,7 +38,7 @@ describe :end_with, shared: true do
   it "uses only the needed arguments" do
     find = mock('h')
     find.should_not_receive(:to_str)
-    "hello".send(@method).should.end_with?("o",find)
+    "hello".send(@method).should.end_with?("o", find)
   end
 
   it "works for multibyte strings" do
@@ -51,4 +51,11 @@ describe :end_with, shared: true do
       "あれ".send(@method).end_with?(pat)
     end.should raise_error(Encoding::CompatibilityError)
   end
+
+  it "checks that we are starting to match at the head of a character" do
+    "\xC3\xA9".send(@method).should_not.end_with?("\xA9")
+    "\xe3\x81\x82".send(@method).should_not.end_with?("\x82")
+    "ab".dup.force_encoding("UTF-16BE").send(@method).should_not.end_with?(
+        "b".dup.force_encoding("UTF-16BE"))
+  end
 end
diff --git a/spec/ruby/shared/string/start_with.rb b/spec/ruby/shared/string/start_with.rb
index d8d6e13f6a..4b947a3bbf 100644
--- a/spec/ruby/shared/string/start_with.rb
+++ b/spec/ruby/shared/string/start_with.rb
@@ -69,4 +69,16 @@ describe :start_with, shared: true do
     Regexp.last_match.should be_nil
     $1.should be_nil
   end
+
+  ruby_version_is ""..."3.3" do
+    it "does not check that we are not matching part of a character" do
+      "\xC3\xA9".send(@method).should.start_with?("\xC3")
+    end
+  end
+
+  ruby_version_is "3.3" do # #19784
+    it "checks that we are not matching part of a character" do
+      "\xC3\xA9".send(@method).should_not.start_with?("\xC3")
+    end
+  end
 end
diff --git a/spec/ruby/shared/string/times.rb b/spec/ruby/shared/string/times.rb
index cd4edf5340..aaf748bad9 100644
--- a/spec/ruby/shared/string/times.rb
+++ b/spec/ruby/shared/string/times.rb
@@ -32,36 +32,14 @@ describe :string_times, shared: true do
     @object.call("", max_long).should == ""
   end
 
-  ruby_version_is ''...'3.0' do
-    it "returns subclass instances" do
-      @object.call(MyString.new("cool"), 0).should be_an_instance_of(MyString)
-      @object.call(MyString.new("cool"), 1).should be_an_instance_of(MyString)
-      @object.call(MyString.new("cool"), 2).should be_an_instance_of(MyString)
-    end
-  end
-
-  ruby_version_is '3.0' do
-    it "returns String instances" do
-      @object.call(MyString.new("cool"), 0).should be_an_instance_of(String)
-      @object.call(MyString.new("cool"), 1).should be_an_instance_of(String)
-      @object.call(MyString.new("cool"), 2).should be_an_instance_of(String)
-    end
-  end
-
-  ruby_version_is ''...'2.7' do
-    it "always taints the result when self is tainted" do
-      ["", "OK", MyString.new(""), MyString.new("OK")].each do |str|
-        str.taint
-
-        [0, 1, 2].each do |arg|
-          @object.call(str, arg).should.tainted?
-        end
-      end
-    end
+  it "returns String instances" do
+    @object.call(MyString.new("cool"), 0).should be_an_instance_of(String)
+    @object.call(MyString.new("cool"), 1).should be_an_instance_of(String)
+    @object.call(MyString.new("cool"), 2).should be_an_instance_of(String)
   end
 
   it "returns a String in the same encoding as self" do
-    str = "\xE3\x81\x82".force_encoding Encoding::UTF_8
+    str = "\xE3\x81\x82".dup.force_encoding Encoding::UTF_8
     result = @object.call(str, 2)
     result.encoding.should equal(Encoding::UTF_8)
   end