3 files changed, 29 insertions, 0 deletions
diff --git a/spec/ruby/core/string/inspect_spec.rb b/spec/ruby/core/string/inspect_spec.rb
index 9818796c83..98b5b32b61 100644
--- a/spec/ruby/core/string/inspect_spec.rb
+++ b/spec/ruby/core/string/inspect_spec.rb
@@ -502,5 +502,11 @@ describe "String#inspect" do
         "\u{3042}".encode("EUC-JP").inspect.should == '"\\x{A4A2}"'
       end
     end
+
+    describe "and the string has both ASCII-compatible and ASCII-incompatible chars" do
+      it "returns a string with the non-ASCII characters replaced by \\u notation" do
+        "hello привет".encode("utf-16le").inspect.should == '"hello \\u043F\\u0440\\u0438\\u0432\\u0435\\u0442"'
+      end
+    end
   end
 end
diff --git a/spec/ruby/core/string/rpartition_spec.rb b/spec/ruby/core/string/rpartition_spec.rb
index c6428636f6..fc37f8b427 100644
--- a/spec/ruby/core/string/rpartition_spec.rb
+++ b/spec/ruby/core/string/rpartition_spec.rb
@@ -11,6 +11,19 @@ describe "String#rpartition with String" do
     "hello".rpartition("hello").should == ["", "hello", ""]
   end
 
+  it "returns original string if regexp doesn't match" do
+    "hello".rpartition("/x/").should == ["", "", "hello"]
+  end
+
+  it "returns new object if doesn't match" do
+    str = "hello"
+    str.rpartition("/no_match/").last.should_not.equal?(str)
+  end
+
+  it "handles multibyte string correctly" do
+    "ユーザ@ドメイン".rpartition(/@/).should == ["ユーザ", "@", "ドメイン"]
+  end
+
   it "accepts regexp" do
     "hello!".rpartition(/l./).should == ["hel", "lo", "!"]
   end
diff --git a/spec/ruby/core/string/split_spec.rb b/spec/ruby/core/string/split_spec.rb
index 2ebfe1e353..e3641b33e0 100644
--- a/spec/ruby/core/string/split_spec.rb
+++ b/spec/ruby/core/string/split_spec.rb
@@ -461,6 +461,16 @@ describe "String#split with Regexp" do
     ->{ broken_str.split(/\r\n|\r|\n/) }.should raise_error(ArgumentError)
   end
 
+  # See https://bugs.ruby-lang.org/issues/12689 and https://github.com/jruby/jruby/issues/4868
+  it "allows concurrent Regexp calls in a shared context" do
+    str = 'a,b,c,d,e'
+
+    p = proc { str.split(/,/) }
+    results = 10.times.map { Thread.new { x = nil; 100.times { x = p.call }; x } }.map(&:value)
+
+    results.should == [%w[a b c d e]] * 10
+  end
+
   ruby_version_is "2.6" do
     context "when a block is given" do
       it "yields each split substring with default pattern" do