[ruby/reline] Support inserting C-c C-z C-\ with quoted_insert

(https://github.com/ruby/reline/pull/798)

https://github.com/ruby/reline/commit/e6eb5d2d3c

lib/reline/io/ansi.rb

@@ -309,6 +309,13 @@ class Reline::ANSI < Reline::IO
     # Signal.trap may raise an ArgumentError if the platform doesn't support the signal.
   end
 
+  def read_single_char(keyseq_timeout)
+    # Disable intr to read `C-c` `C-z` `C-\` for quoted insert
+    @input.raw(intr: false) do
+      super
+    end
+  end
+
   def prep
     # Enable bracketed paste
     write "\e[?2004h" if Reline.core.config.enable_bracketed_paste && both_tty?

lib/reline/unicode.rb

@@ -28,6 +28,7 @@ class Reline::Unicode
     0x19 => '^Y',
     0x1A => '^Z', # C-z
     0x1B => '^[', # C-[ C-3
+    0x1C => '^\\', # C-\
     0x1D => '^]', # C-]
     0x1E => '^^', # C-~ C-6
     0x1F => '^_', # C-_ C-7

test/reline/yamatanooroti/test_rendering.rb

@@ -1724,6 +1724,26 @@ begin
       close
     end
 
+    def test_quoted_insert_intr_keys
+      omit if Reline.core.io_gate.win?
+      start_terminal(5, 30, %W{ruby -I#{@pwd}/lib #{@pwd}/test/reline/yamatanooroti/multiline_repl}, startup_message: 'Multiline REPL.')
+      write '"'
+      write "\C-v"
+      write "\C-c"
+      write "\C-v"
+      write "\C-z"
+      write "\C-v"
+      write "\C-\\"
+      write "\".bytes\n"
+      assert_screen(<<~EOC)
+        Multiline REPL.
+        prompt> "^C^Z^\\\".bytes
+        => [3, 26, 28]
+        prompt>
+      EOC
+      close
+    end
+
     def test_print_before_readline
       code = <<~RUBY
         puts 'Multiline REPL.'