Work with wrong $/ value correctly

lib/reline.rb

@@ -175,7 +175,7 @@ def readmultiline(prompt = '', add_hist = false, &confirm_multiline_termination)
 
       whole_buffer = line_editor.whole_buffer.dup
       whole_buffer.taint if RUBY_VERSION < '2.7'
-      if add_hist and whole_buffer and whole_buffer.chomp.size > 0
+      if add_hist and whole_buffer and whole_buffer.chomp("\n").size > 0
         Reline::HISTORY << whole_buffer
       end
 
@@ -188,8 +188,8 @@ def readline(prompt = '', add_hist = false)
 
       line = line_editor.line.dup
       line.taint if RUBY_VERSION < '2.7'
-      if add_hist and line and line.chomp.size > 0
-        Reline::HISTORY << line.chomp
+      if add_hist and line and line.chomp("\n").size > 0
+        Reline::HISTORY << line.chomp("\n")
       end
 
       line_editor.reset_line if line_editor.line.nil?

lib/reline/line_editor.rb

@@ -543,7 +543,7 @@ def rerender
     return before if before.nil? || before.empty?
 
     if after = @output_modifier_proc&.call("#{before.join("\n")}\n", complete: finished?)
-      after.lines(chomp: true)
+      after.lines("\n", chomp: true)
     else
       before
     end

test/reline/test_key_actor_emacs.rb

@@ -1896,6 +1896,15 @@ def test_em_set_mark_and_em_exchange_mark
     assert_equal([0, 0], @line_editor.instance_variable_get(:@mark_pointer))
   end
 
+  def test_modify_lines_with_wrong_rs
+    original_global_slash = $/
+    $/ = 'b'
+    @line_editor.output_modifier_proc = proc { |output| Reline::Unicode.escape_for_print(output) }
+    input_keys("abcdef\n")
+    assert_equal(['abcdef'], @line_editor.__send__(:modify_lines, @line_editor.whole_lines))
+    $/ = original_global_slash
+  end
+
 =begin # TODO: move KeyStroke instance from Reline to LineEditor
   def test_key_delete
     input_keys('ab')