Merge IRB 1.2.6

29 files changed, 913 insertions, 106 deletions

diff --git a/lib/irb.rb b/lib/irb.rb
index ee6979c6d0..d8e1209f2c 100644
--- a/lib/irb.rb
+++ b/lib/irb.rb
@@ -10,18 +10,19 @@
 #
 #
 require "ripper"
+require "reline"
 
-require "irb/init"
-require "irb/context"
-require "irb/extend-command"
+require_relative "irb/init"
+require_relative "irb/context"
+require_relative "irb/extend-command"
 
-require "irb/ruby-lex"
-require "irb/input-method"
-require "irb/locale"
-require "irb/color"
+require_relative "irb/ruby-lex"
+require_relative "irb/input-method"
+require_relative "irb/locale"
+require_relative "irb/color"
 
-require "irb/version"
-require "irb/easter-egg"
+require_relative "irb/version"
+require_relative "irb/easter-egg"
 
 # IRB stands for "interactive Ruby" and is a tool to interactively execute Ruby
 # expressions read from the standard input.
@@ -271,7 +272,7 @@ require "irb/easter-egg"
 # On the other hand, each conf in IRB@Command+line+options is used to
 # individually configure IRB.irb.
 #
-# If a proc is set for IRB.conf[:IRB_RC], its will be invoked after execution
+# If a proc is set for <code>IRB.conf[:IRB_RC]</code>, its will be invoked after execution
 # of that proc with the context of the current session as its argument. Each
 # session can be configured using this mechanism.
 #
@@ -399,7 +400,7 @@ module IRB
     irb.run(@CONF)
   end
 
-  # Calls each event hook of IRB.conf[:AT_EXIT] when the current session quits.
+  # Calls each event hook of <code>IRB.conf[:TA_EXIT]</code> when the current session quits.
   def IRB.irb_at_exit
     @CONF[:AT_EXIT].each{|hook| hook.call}
   end
@@ -538,7 +539,15 @@ module IRB
           begin
             line.untaint if RUBY_VERSION < '2.7'
             @context.evaluate(line, line_no, exception: exc)
-            output_value if @context.echo? && (@context.echo_on_assignment? || !assignment_expression?(line))
+            if @context.echo?
+              if assignment_expression?(line)
+                if @context.echo_on_assignment?
+                  output_value(@context.omit_on_assignment?)
+                end
+              else
+                output_value
+              end
+            end
           rescue Interrupt => exc
           rescue SystemExit, SignalException
             raise
@@ -737,9 +746,32 @@ module IRB
       p
     end
 
-    def output_value # :nodoc:
+    def output_value(omit = false) # :nodoc:
       str = @context.inspect_last_value
       multiline_p = str.include?("\n")
+      if omit
+        winwidth = @context.io.winsize.last
+        if multiline_p
+          first_line = str.split("\n").first
+          result = @context.newline_before_multiline_output? ? (@context.return_format % first_line) : first_line
+          output_width = Reline::Unicode.calculate_width(result, true)
+          diff_size = output_width - Reline::Unicode.calculate_width(first_line, true)
+          if diff_size.positive? and output_width > winwidth
+            lines, _ = Reline::Unicode.split_by_width(first_line, winwidth - diff_size - 3)
+            str = "%s...\e[0m" % lines.first
+            multiline_p = false
+          else
+            str.gsub!(/(\A.*?\n).*/m, "\\1...")
+          end
+        else
+          output_width = Reline::Unicode.calculate_width(@context.return_format % str, true)
+          diff_size = output_width - Reline::Unicode.calculate_width(str, true)
+          if diff_size.positive? and output_width > winwidth
+            lines, _ = Reline::Unicode.split_by_width(str, winwidth - diff_size - 3)
+            str = "%s...\e[0m" % lines.first
+          end
+        end
+      end
       if multiline_p && @context.newline_before_multiline_output?
         printf @context.return_format, "\n#{str}"
       else
diff --git a/lib/irb/cmd/fork.rb b/lib/irb/cmd/fork.rb
index 31d53dcaba..19c78fc910 100644
--- a/lib/irb/cmd/fork.rb
+++ b/lib/irb/cmd/fork.rb
@@ -35,5 +35,3 @@ module IRB
   end
 end
 # :startdoc:
-
-
diff --git a/lib/irb/cmd/info.rb b/lib/irb/cmd/info.rb
new file mode 100644
index 0000000000..53ec71d754
--- /dev/null
+++ b/lib/irb/cmd/info.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: false
+
+require_relative "nop"
+
+# :stopdoc:
+module IRB
+  module ExtendCommand
+    class Info < Nop
+      def execute
+        Class.new {
+          def inspect
+            str  = "Ruby version: #{RUBY_VERSION}\n"
+            str += "IRB version: #{IRB.version}\n"
+            str += "InputMethod: #{IRB.CurrentContext.io.inspect}\n"
+            str += ".irbrc path: #{IRB.rc_file}\n" if File.exist?(IRB.rc_file)
+            str
+          end
+          alias_method :to_s, :inspect
+        }.new
+      end
+    end
+  end
+end
+# :startdoc:
diff --git a/lib/irb/cmd/pushws.rb b/lib/irb/cmd/pushws.rb
index 187b276e48..612157d8a0 100644
--- a/lib/irb/cmd/pushws.rb
+++ b/lib/irb/cmd/pushws.rb
@@ -38,4 +38,3 @@ module IRB
   end
 end
 # :startdoc:
-
diff --git a/lib/irb/color.rb b/lib/irb/color.rb
index d2b9674a71..0f49291d85 100644
--- a/lib/irb/color.rb
+++ b/lib/irb/color.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 require 'reline'
 require 'ripper'
+require 'irb/ruby-lex'
 
 module IRB # :nodoc:
   module Color
@@ -145,37 +146,38 @@ module IRB # :nodoc:
         seen.delete(obj)
       end
 
-      # Ripper::Lexer::Elem#state is supported on Ruby 2.5+
       def supported?
         return @supported if defined?(@supported)
-        @supported = Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('2.5.0')
+        @supported = Ripper::Lexer::Elem.method_defined?(:state)
       end
 
       def scan(code, allow_last_error:)
         pos = [1, 0]
 
         verbose, $VERBOSE = $VERBOSE, nil
-        lexer = Ripper::Lexer.new(code)
-        if lexer.respond_to?(:scan) # Ruby 2.7+
-          lexer.scan.each do |elem|
-            str = elem.tok
-            next if allow_last_error and /meets end of file|unexpected end-of-input/ =~ elem.message
-            next if ([elem.pos[0], elem.pos[1] + str.bytesize] <=> pos) <= 0
-
-            str.each_line do |line|
-              if line.end_with?("\n")
-                pos[0] += 1
-                pos[1] = 0
-              else
-                pos[1] += line.bytesize
+        RubyLex.compile_with_errors_suppressed(code) do |inner_code, line_no|
+          lexer = Ripper::Lexer.new(inner_code, '(ripper)', line_no)
+          if lexer.respond_to?(:scan) # Ruby 2.7+
+            lexer.scan.each do |elem|
+              str = elem.tok
+              next if allow_last_error and /meets end of file|unexpected end-of-input/ =~ elem.message
+              next if ([elem.pos[0], elem.pos[1] + str.bytesize] <=> pos) <= 0
+
+              str.each_line do |line|
+                if line.end_with?("\n")
+                  pos[0] += 1
+                  pos[1] = 0
+                else
+                  pos[1] += line.bytesize
+                end
               end
-            end
 
-            yield(elem.event, str, elem.state)
-          end
-        else
-          lexer.parse.each do |elem|
-            yield(elem.event, elem.tok, elem.state)
+              yield(elem.event, str, elem.state)
+            end
+          else
+            lexer.parse.each do |elem|
+              yield(elem.event, elem.tok, elem.state)
+            end
           end
         end
         $VERBOSE = verbose
diff --git a/lib/irb/completion.rb b/lib/irb/completion.rb
index c44aa9039e..c9328e5c5a 100644
--- a/lib/irb/completion.rb
+++ b/lib/irb/completion.rb
@@ -7,7 +7,6 @@
 #       From Original Idea of shugo@ruby-lang.org
 #
 
-require "readline"
 autoload :RDoc, "rdoc"
 
 module IRB
@@ -97,17 +96,13 @@ module IRB
       when /^(:[^:.]*)$/
         # Symbol
         return nil if doc_namespace
-        if Symbol.respond_to?(:all_symbols)
-          sym = $1
-          candidates = Symbol.all_symbols.collect do |s|
-            ":" + s.id2name.encode(Encoding.default_external)
-          rescue Encoding::UndefinedConversionError
-            # ignore
-          end
-          candidates.grep(/^#{Regexp.quote(sym)}/)
-        else
-          []
+        sym = $1
+        candidates = Symbol.all_symbols.collect do |s|
+          ":" + s.id2name.encode(Encoding.default_external)
+        rescue Encoding::UndefinedConversionError
+          # ignore
         end
+        candidates.grep(/^#{Regexp.quote(sym)}/)
 
       when /^::([A-Z][^:\.\(]*)$/
         # Absolute Constant or class methods
diff --git a/lib/irb/context.rb b/lib/irb/context.rb
index 218f7c6037..4f001729e1 100644
--- a/lib/irb/context.rb
+++ b/lib/irb/context.rb
@@ -131,7 +131,12 @@ module IRB
 
       @echo_on_assignment = IRB.conf[:ECHO_ON_ASSIGNMENT]
       if @echo_on_assignment.nil?
-        @echo_on_assignment = false
+        @echo_on_assignment = true
+      end
+
+      @omit_on_assignment = IRB.conf[:OMIT_ON_ASSIGNMENT]
+      if @omit_on_assignment.nil?
+        @omit_on_assignment = true
       end
 
       @newline_before_multiline_output = IRB.conf[:NEWLINE_BEFORE_MULTILINE_OUTPUT]
@@ -240,7 +245,7 @@ module IRB
     attr_accessor :ignore_eof
     # Whether to echo the return value to output or not.
     #
-    # Uses IRB.conf[:ECHO] if available, or defaults to +true+.
+    # Uses <code>IRB.conf[:ECHO]</code> if available, or defaults to +true+.
     #
     #     puts "hello"
     #     # hello
@@ -251,16 +256,30 @@ module IRB
     attr_accessor :echo
     # Whether to echo for assignment expressions
     #
-    # Uses IRB.conf[:ECHO_ON_ASSIGNMENT] if available, or defaults to +false+.
+    # Uses <code>IRB.conf[:ECHO_ON_ASSIGNMENT]</code> if available, or defaults to +true+.
     #
     #     a = "omg"
-    #     IRB.CurrentContext.echo_on_assignment = true
-    #     a = "omg"
     #     #=> omg
+    #     IRB.CurrentContext.echo_on_assignment = false
+    #     a = "omg"
     attr_accessor :echo_on_assignment
+    # Whether to omit echo for assignment expressions
+    #
+    # Uses <code>IRB.conf[:OMIT_ON_ASSIGNMENT]</code> if available, or defaults to +true+.
+    #
+    #     a = [1] * 10
+    #     #=> [1, 1, 1, 1, 1, 1, 1, 1, ...
+    #     [1] * 10
+    #     #=> [1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
+    #     IRB.CurrentContext.omit_on_assignment = false
+    #     a = [1] * 10
+    #     #=> [1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
+    #     [1] * 10
+    #     #=> [1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
+    attr_accessor :omit_on_assignment
     # Whether a newline is put before multiline output.
     #
-    # Uses IRB.conf[:NEWLINE_BEFORE_MULTILINE_OUTPUT] if available,
+    # Uses <code>IRB.conf[:NEWLINE_BEFORE_MULTILINE_OUTPUT]</code> if available,
     # or defaults to +true+.
     #
     #     "abc\ndef"
@@ -306,6 +325,7 @@ module IRB
     alias ignore_eof? ignore_eof
     alias echo? echo
     alias echo_on_assignment? echo_on_assignment
+    alias omit_on_assignment? omit_on_assignment
     alias newline_before_multiline_output? newline_before_multiline_output
 
     # Returns whether messages are displayed or not.
diff --git a/lib/irb/ext/change-ws.rb b/lib/irb/ext/change-ws.rb
index 94bfe62bc0..4c57e44eab 100644
--- a/lib/irb/ext/change-ws.rb
+++ b/lib/irb/ext/change-ws.rb
@@ -43,4 +43,3 @@ module IRB # :nodoc:
     end
   end
 end
-
diff --git a/lib/irb/ext/history.rb b/lib/irb/ext/history.rb
index 30e3fb901f..fc304c6f6c 100644
--- a/lib/irb/ext/history.rb
+++ b/lib/irb/ext/history.rb
@@ -153,5 +153,3 @@ module IRB # :nodoc:
     end
   end
 end
-
-
diff --git a/lib/irb/ext/loader.rb b/lib/irb/ext/loader.rb
index 840226db30..1b683d88e5 100644
--- a/lib/irb/ext/loader.rb
+++ b/lib/irb/ext/loader.rb
@@ -126,4 +126,3 @@ module IRB # :nodoc:
     end
   end
 end
-
diff --git a/lib/irb/ext/save-history.rb b/lib/irb/ext/save-history.rb
index edc4f234cc..ac358c8ccb 100644
--- a/lib/irb/ext/save-history.rb
+++ b/lib/irb/ext/save-history.rb
@@ -9,8 +9,6 @@
 #
 #
 
-require "readline"
-
 module IRB
   module HistorySavingAbility # :nodoc:
   end
@@ -27,7 +25,7 @@ module IRB
       IRB.conf[:SAVE_HISTORY]
     end
 
-    remove_method :save_history= if method_defined?(:save_history=)
+    remove_method(:save_history=) if method_defined?(:save_history=)
     # Sets <code>IRB.conf[:SAVE_HISTORY]</code> to the given +val+ and calls
     # #init_save_history with this context.
     #
@@ -89,7 +87,7 @@ module IRB
     def save_history
       return unless self.class.const_defined?(:HISTORY)
       history = self.class::HISTORY
-      if num = IRB.conf[:SAVE_HISTORY] and (num = num.to_i) > 0
+      if num = IRB.conf[:SAVE_HISTORY] and (num = num.to_i) != 0
         if history_file = IRB.conf[:HISTORY_FILE]
           history_file = File.expand_path(history_file)
         end
@@ -109,7 +107,12 @@ module IRB
 
         open(history_file, "w:#{IRB.conf[:LC_MESSAGES].encoding}", 0600) do |f|
           hist = history.map{ |l| l.split("\n").join("\\\n") }
-          f.puts(hist[-num..-1] || hist)
+          begin
+            hist = hist.last(num) if hist.size > num and num > 0
+          rescue RangeError # bignum too big to convert into `long'
+            # Do nothing because the bignum should be treated as inifinity
+          end
+          f.puts(hist)
         end
       end
     end
diff --git a/lib/irb/ext/tracer.rb b/lib/irb/ext/tracer.rb
index e3e325e6e5..67ac4bb965 100644
--- a/lib/irb/ext/tracer.rb
+++ b/lib/irb/ext/tracer.rb
@@ -82,4 +82,3 @@ module IRB
 
   IRB.initialize_tracer
 end
-
diff --git a/lib/irb/ext/use-loader.rb b/lib/irb/ext/use-loader.rb
index cb10e8a254..1897bc89e0 100644
--- a/lib/irb/ext/use-loader.rb
+++ b/lib/irb/ext/use-loader.rb
@@ -47,7 +47,7 @@ module IRB
     alias use_loader? use_loader
 
     remove_method :use_loader= if method_defined?(:use_loader=)
-    # Sets IRB.conf[:USE_LOADER]
+    # Sets <code>IRB.conf[:USE_LOADER]</code>
     #
     # See #use_loader for more information.
     def use_loader=(opt)
@@ -73,5 +73,3 @@ module IRB
     end
   end
 end
-
-
diff --git a/lib/irb/ext/workspaces.rb b/lib/irb/ext/workspaces.rb
index 5bd72c194f..730b58e64d 100644
--- a/lib/irb/ext/workspaces.rb
+++ b/lib/irb/ext/workspaces.rb
@@ -64,4 +64,3 @@ module IRB # :nodoc:
     end
   end
 end
-
diff --git a/lib/irb/extend-command.rb b/lib/irb/extend-command.rb
index de145e962d..2f4fcfb5c6 100644
--- a/lib/irb/extend-command.rb
+++ b/lib/irb/extend-command.rb
@@ -121,6 +121,10 @@ module IRB # :nodoc:
         [:help, NO_OVERRIDE],
       ],
 
+      [
+        :irb_info, :Info, "irb/cmd/info"
+      ],
+
     ]
 
     # Installs the default irb commands:
@@ -169,11 +173,14 @@ module IRB # :nodoc:
             args << "&block"
             args = args.join(", ")
             line = __LINE__; eval %[
-              def #{cmd_name}(\#{args})
-            ExtendCommand::#{cmd_class}.execute(irb_context, \#{args})
+              unless self.class.class_variable_defined?(:@@#{cmd_name}_)
+              self.class.class_variable_set(:@@#{cmd_name}_, true)
+                def #{cmd_name}_(\#{args})
+                  ExtendCommand::#{cmd_class}.execute(irb_context, \#{args})
+                end
               end
             ], nil, __FILE__, line
-            send :#{cmd_name}, *opts, &b
+            send :#{cmd_name}_, *opts, &b
           end
         ], nil, __FILE__, line
       else
diff --git a/lib/irb/help.rb b/lib/irb/help.rb
index 7868a70a6c..3eeaf841b0 100644
--- a/lib/irb/help.rb
+++ b/lib/irb/help.rb
@@ -34,4 +34,3 @@ module IRB
     }
   end
 end
-
diff --git a/lib/irb/init.rb b/lib/irb/init.rb
index 37d1f8d609..44383609bd 100644
--- a/lib/irb/init.rb
+++ b/lib/irb/init.rb
@@ -52,6 +52,7 @@ module IRB # :nodoc:
     @CONF[:IGNORE_EOF] = false
     @CONF[:ECHO] = nil
     @CONF[:ECHO_ON_ASSIGNMENT] = nil
+    @CONF[:OMIT_ON_ASSIGNMENT] = nil
     @CONF[:VERBOSE] = nil
 
     @CONF[:EVAL_HISTORY] = nil
@@ -177,6 +178,10 @@ module IRB # :nodoc:
         @CONF[:ECHO_ON_ASSIGNMENT] = true
       when "--noecho-on-assignment"
         @CONF[:ECHO_ON_ASSIGNMENT] = false
+      when "--omit-on-assignment"
+        @CONF[:OMIT_ON_ASSIGNMENT] = true
+      when "--noomit-on-assignment"
+        @CONF[:OMIT_ON_ASSIGNMENT] = false
       when "--verbose"
         @CONF[:VERBOSE] = true
       when "--noverbose"
@@ -271,10 +276,19 @@ module IRB # :nodoc:
     if irbrc = ENV["IRBRC"]
       yield proc{|rc| rc == "rc" ? irbrc : irbrc+rc}
     end
+    if xdg_config_home = ENV["XDG_CONFIG_HOME"]
+      irb_home = File.join(xdg_config_home, "irb")
+      unless File.exist? irb_home
+        require 'fileutils'
+        FileUtils.mkdir_p irb_home
+      end
+      yield proc{|rc| irb_home + "/irb#{rc}"}
+    end
     if home = ENV["HOME"]
       yield proc{|rc| home+"/.irb#{rc}"}
     end
     current_dir = Dir.pwd
+    yield proc{|rc| current_dir+"/.config/irb/irb#{rc}"}
     yield proc{|rc| current_dir+"/.irb#{rc}"}
     yield proc{|rc| current_dir+"/irb#{rc.sub(/\A_?/, '.')}"}
     yield proc{|rc| current_dir+"/_irb#{rc}"}
diff --git a/lib/irb/input-method.rb b/lib/irb/input-method.rb
index 9fbbaeb0f3..6e87488753 100644
--- a/lib/irb/input-method.rb
+++ b/lib/irb/input-method.rb
@@ -12,6 +12,7 @@
 require_relative 'src_encoding'
 require_relative 'magic-file'
 require_relative 'completion'
+require 'io/console'
 require 'reline'
 
 module IRB
@@ -36,6 +37,14 @@ module IRB
     end
     public :gets
 
+    def winsize
+      if instance_variable_defined?(:@stdout)
+        @stdout.winsize
+      else
+        [24, 80]
+      end
+    end
+
     # Whether this input method is still readable when there is no more data to
     # read.
     #
@@ -43,6 +52,11 @@ module IRB
     def readable_after_eof?
       false
     end
+
+    # For debug message
+    def inspect
+      'Abstract InputMethod'
+    end
   end
 
   class StdioInputMethod < InputMethod
@@ -93,6 +107,11 @@ module IRB
     def encoding
       @stdin.external_encoding
     end
+
+    # For debug message
+    def inspect
+      'StdioInputMethod'
+    end
   end
 
   # Use a File for IO with irb, see InputMethod
@@ -125,14 +144,25 @@ module IRB
     def encoding
       @io.external_encoding
     end
+
+    # For debug message
+    def inspect
+      'FileInputMethod'
+    end
   end
 
   begin
-    require "readline"
     class ReadlineInputMethod < InputMethod
-      include Readline
+      def self.initialize_readline
+        require "readline"
+      rescue LoadError
+      else
+        include ::Readline
+      end
+
       # Creates a new input method object using Readline
       def initialize
+        self.class.initialize_readline
         if Readline.respond_to?(:encoding_system_needs)
           IRB.__send__(:set_encoding, Readline.encoding_system_needs.name, override: false)
         end
@@ -197,13 +227,15 @@ module IRB
         @stdin.external_encoding
       end
 
-      if Readline.respond_to?("basic_word_break_characters=")
-        Readline.basic_word_break_characters = IRB::InputCompletor::BASIC_WORD_BREAK_CHARACTERS
+      # For debug message
+      def inspect
+        readline_impl = (defined?(Reline) && Readline == Reline) ? 'Reline' : 'ext/readline'
+        str = "ReadlineInputMethod with #{readline_impl} #{Readline::VERSION}"
+        inputrc_path = File.expand_path(ENV['INPUTRC'] || '~/.inputrc')
+        str += " and #{inputrc_path}" if File.exist?(inputrc_path)
+        str
       end
-      Readline.completion_append_character = nil
-      Readline.completion_proc = IRB::InputCompletor::CompletionProc
     end
-  rescue LoadError
   end
 
   class ReidlineInputMethod < InputMethod
@@ -227,7 +259,7 @@ module IRB
       Reline.completion_proc = IRB::InputCompletor::CompletionProc
       Reline.output_modifier_proc =
         if IRB.conf[:USE_COLORIZE]
-          proc do |output, complete:|
+          proc do |output, complete: |
             next unless IRB::Color.colorable?
             IRB::Color.colorize_code(output, complete: complete)
           end
@@ -297,5 +329,18 @@ module IRB
     def encoding
       @stdin.external_encoding
     end
+
+    # For debug message
+    def inspect
+      config = Reline::Config.new
+      str = "ReidlineInputMethod with Reline #{Reline::VERSION}"
+      if config.respond_to?(:inputrc_path)
+        inputrc_path = File.expand_path(config.inputrc_path)
+      else
+        inputrc_path = File.expand_path(ENV['INPUTRC'] || '~/.inputrc')
+      end
+      str += " and #{inputrc_path}" if File.exist?(inputrc_path)
+      str
+    end
   end
 end
diff --git a/lib/irb/inspector.rb b/lib/irb/inspector.rb
index bc7fb0b125..671b32b6e8 100644
--- a/lib/irb/inspector.rb
+++ b/lib/irb/inspector.rb
@@ -113,6 +113,7 @@ module IRB # :nodoc:
       result
     rescue NoMethodError
       puts "(Object doesn't support #inspect)"
+      ''
     end
   }
   Inspector.def_inspector([:pp, :pretty_inspect], proc{require "pp"}){|v|
@@ -135,8 +136,3 @@ module IRB # :nodoc:
     Marshal.dump(v)
   }
 end
-
-
-
-
-
diff --git a/lib/irb/irb.gemspec b/lib/irb/irb.gemspec
index 658fe813f1..af40a32452 100644
--- a/lib/irb/irb.gemspec
+++ b/lib/irb/irb.gemspec
@@ -14,7 +14,7 @@ Gem::Specification.new do |spec|
   spec.summary       = %q{Interactive Ruby command-line tool for REPL (Read Eval Print Loop).}
   spec.description   = %q{Interactive Ruby command-line tool for REPL (Read Eval Print Loop).}
   spec.homepage      = "https://github.com/ruby/irb"
-  spec.license       = "BSD-2-Clause"
+  spec.licenses      = ["Ruby", "BSD-2-Clause"]
 
   spec.files         = [
     ".document",
@@ -78,7 +78,7 @@ Gem::Specification.new do |spec|
 
   spec.required_ruby_version = Gem::Requirement.new(">= 2.5")
 
-  spec.add_dependency "reline", ">= 0.0.1"
+  spec.add_dependency "reline", ">= 0.1.5"
   spec.add_development_dependency "bundler"
   spec.add_development_dependency "rake"
 end
diff --git a/lib/irb/ruby-lex.rb b/lib/irb/ruby-lex.rb
index d5630c8b52..7be77fd12e 100644
--- a/lib/irb/ruby-lex.rb
+++ b/lib/irb/ruby-lex.rb
@@ -11,6 +11,7 @@
 #
 
 require "ripper"
+require "jruby" if RUBY_ENGINE == "jruby"
 
 # :stopdoc:
 class RubyLex
@@ -29,6 +30,18 @@ class RubyLex
     @prompt = nil
   end
 
+  def self.compile_with_errors_suppressed(code)
+    line_no = 1
+    begin
+      result = yield code, line_no
+    rescue ArgumentError
+      code = ";\n#{code}"
+      line_no = 0
+      result = yield code, line_no
+    end
+    result
+  end
+
   # io functions
   def set_input(io, p = nil, &block)
     @io = io
@@ -75,7 +88,10 @@ class RubyLex
 
   def ripper_lex_without_warning(code)
     verbose, $VERBOSE = $VERBOSE, nil
-    tokens = Ripper.lex(code)
+    tokens = nil
+    self.class.compile_with_errors_suppressed(code) do |inner_code, line_no|
+      tokens = Ripper.lex(inner_code, '-', line_no)
+    end
     $VERBOSE = verbose
     tokens
   end
@@ -209,7 +225,9 @@ class RubyLex
       when 'jruby'
         JRuby.compile_ir(code)
       else
-        RubyVM::InstructionSequence.compile(code)
+        self.class.compile_with_errors_suppressed(code) do |inner_code, line_no|
+          RubyVM::InstructionSequence.compile(inner_code, nil, nil, line_no)
+        end
       end
     rescue EncodingError
       # This is for a hash with invalid encoding symbol, {"\xAE": 1}
@@ -285,9 +303,33 @@ class RubyLex
 
   def process_nesting_level
     indent = 0
+    in_oneliner_def = nil
     @tokens.each_with_index { |t, index|
+      # detecting one-liner method definition
+      if in_oneliner_def.nil?
+        if t[3].allbits?(Ripper::EXPR_ENDFN)
+          in_oneliner_def = :ENDFN
+        end
+      else
+        if t[3].allbits?(Ripper::EXPR_ENDFN)
+          # continuing
+        elsif t[3].allbits?(Ripper::EXPR_BEG)
+          if t[2] == '='
+            in_oneliner_def = :BODY
+          end
+        elsif t[3].allbits?(Ripper::EXPR_END)
+          if in_oneliner_def == :BODY
+            # one-liner method definition
+            indent -= 1
+          end
+          in_oneliner_def = nil
+        else
+          in_oneliner_def = nil
+        end
+      end
+
       case t[1]
-      when :on_lbracket, :on_lbrace, :on_lparen
+      when :on_lbracket, :on_lbrace, :on_lparen, :on_tlambeg
         indent += 1
       when :on_rbracket, :on_rbrace, :on_rparen
         indent -= 1
@@ -306,7 +348,7 @@ class RubyLex
         when 'def', 'case', 'for', 'begin', 'class', 'module'
           indent += 1
         when 'if', 'unless', 'while', 'until'
-          # postfix if/unless/while/until/rescue must be Ripper::EXPR_LABEL
+          # postfix if/unless/while/until must be Ripper::EXPR_LABEL
           indent += 1 unless t[3].allbits?(Ripper::EXPR_LABEL)
         when 'end'
           indent -= 1
@@ -320,7 +362,31 @@ class RubyLex
   def check_newline_depth_difference
     depth_difference = 0
     open_brace_on_line = 0
+    in_oneliner_def = nil
     @tokens.each_with_index do |t, index|
+      # detecting one-liner method definition
+      if in_oneliner_def.nil?
+        if t[3].allbits?(Ripper::EXPR_ENDFN)
+          in_oneliner_def = :ENDFN
+        end
+      else
+        if t[3].allbits?(Ripper::EXPR_ENDFN)
+          # continuing
+        elsif t[3].allbits?(Ripper::EXPR_BEG)
+          if t[2] == '='
+            in_oneliner_def = :BODY
+          end
+        elsif t[3].allbits?(Ripper::EXPR_END)
+          if in_oneliner_def == :BODY
+            # one[-liner method definition
+            depth_difference -= 1
+          end
+          in_oneliner_def = nil
+        else
+          in_oneliner_def = nil
+        end
+      end
+
       case t[1]
       when :on_ignored_nl, :on_nl, :on_comment
         if index != (@tokens.size - 1)
@@ -332,7 +398,7 @@ class RubyLex
         next
       end
       case t[1]
-      when :on_lbracket, :on_lbrace, :on_lparen
+      when :on_lbracket, :on_lbrace, :on_lparen, :on_tlambeg
         depth_difference += 1
         open_brace_on_line += 1
       when :on_rbracket, :on_rbrace, :on_rparen
@@ -351,12 +417,12 @@ class RubyLex
           end
         when 'def', 'case', 'for', 'begin', 'class', 'module'
           depth_difference += 1
-        when 'if', 'unless', 'while', 'until'
+        when 'if', 'unless', 'while', 'until', 'rescue'
           # postfix if/unless/while/until/rescue must be Ripper::EXPR_LABEL
           unless t[3].allbits?(Ripper::EXPR_LABEL)
             depth_difference += 1
           end
-        when 'else', 'elsif', 'rescue', 'ensure', 'when', 'in'
+        when 'else', 'elsif', 'ensure', 'when', 'in'
           depth_difference += 1
         end
       end
@@ -371,7 +437,36 @@ class RubyLex
     spaces_of_nest = []
     spaces_at_line_head = 0
     open_brace_on_line = 0
+    in_oneliner_def = nil
     @tokens.each_with_index do |t, index|
+      # detecting one-liner method definition
+      if in_oneliner_def.nil?
+        if t[3].allbits?(Ripper::EXPR_ENDFN)
+          in_oneliner_def = :ENDFN
+        end
+      else
+        if t[3].allbits?(Ripper::EXPR_ENDFN)
+          # continuing
+        elsif t[3].allbits?(Ripper::EXPR_BEG)
+          if t[2] == '='
+            in_oneliner_def = :BODY
+          end
+        elsif t[3].allbits?(Ripper::EXPR_END)
+          if in_oneliner_def == :BODY
+            # one-liner method definition
+            if is_first_printable_of_line
+              corresponding_token_depth = spaces_of_nest.pop
+            else
+              spaces_of_nest.pop
+              corresponding_token_depth = nil
+            end
+          end
+          in_oneliner_def = nil
+        else
+          in_oneliner_def = nil
+        end
+      end
+
       case t[1]
       when :on_ignored_nl, :on_nl, :on_comment
         corresponding_token_depth = nil
@@ -386,7 +481,7 @@ class RubyLex
         next
       end
       case t[1]
-      when :on_lbracket, :on_lbrace, :on_lparen
+      when :on_lbracket, :on_lbrace, :on_lparen, :on_tlambeg
         spaces_of_nest.push(spaces_at_line_head + open_brace_on_line * 2)
         open_brace_on_line += 1
       when :on_rbracket, :on_rbrace, :on_rparen
@@ -402,12 +497,16 @@ class RubyLex
         case t[2]
         when 'def', 'do', 'case', 'for', 'begin', 'class', 'module'
           spaces_of_nest.push(spaces_at_line_head)
+        when 'rescue'
+          unless t[3].allbits?(Ripper::EXPR_LABEL)
+            corresponding_token_depth = spaces_of_nest.last
+          end
         when 'if', 'unless', 'while', 'until'
-          # postfix if/unless/while/until/rescue must be Ripper::EXPR_LABEL
+          # postfix if/unless/while/until must be Ripper::EXPR_LABEL
           unless t[3].allbits?(Ripper::EXPR_LABEL)
             spaces_of_nest.push(spaces_at_line_head)
           end
-        when 'else', 'elsif', 'rescue', 'ensure', 'when', 'in'
+        when 'else', 'elsif', 'ensure', 'when', 'in'
           corresponding_token_depth = spaces_of_nest.last
         when 'end'
           if is_first_printable_of_line
diff --git a/lib/irb/ruby_logo.aa b/lib/irb/ruby_logo.aa
index 043e6f85fb..a34a3e2f28 100644
--- a/lib/irb/ruby_logo.aa
+++ b/lib/irb/ruby_logo.aa
@@ -35,4 +35,3 @@
     m7       NW H            N                        HSVO1z=?11-
       NgTH    bB        kH   WBHWWHBHWmQgg&gggggNNN
            NNggggggNN
-
diff --git a/lib/irb/version.rb b/lib/irb/version.rb
index 7669c1c535..8b61eb3ef9 100644
--- a/lib/irb/version.rb
+++ b/lib/irb/version.rb
@@ -11,7 +11,7 @@
 #
 
 module IRB # :nodoc:
-  VERSION = "1.2.3"
+  VERSION = "1.2.6"
   @RELEASE_VERSION = VERSION
-  @LAST_UPDATE_DATE = "2020-02-15"
+  @LAST_UPDATE_DATE = "2020-09-14"
 end
diff --git a/lib/irb/xmp.rb b/lib/irb/xmp.rb
index 60cf3b4e4d..88cbd88525 100644
--- a/lib/irb/xmp.rb
+++ b/lib/irb/xmp.rb
@@ -10,7 +10,7 @@
 #
 #
 
-require "irb"
+require_relative "../irb"
 require_relative "frame"
 
 # An example printer for irb.
diff --git a/test/irb/test_cmd.rb b/test/irb/test_cmd.rb
new file mode 100644
index 0000000000..bb33f535b6
--- /dev/null
+++ b/test/irb/test_cmd.rb
@@ -0,0 +1,127 @@
+# frozen_string_literal: false
+require "test/unit"
+require "irb"
+require "irb/extend-command"
+
+module TestIRB
+  class ExtendCommand < Test::Unit::TestCase
+    def setup
+      @pwd = Dir.pwd
+      @tmpdir = File.join(Dir.tmpdir, "test_reline_config_#{$$}")
+      begin
+        Dir.mkdir(@tmpdir)
+      rescue Errno::EEXIST
+        FileUtils.rm_rf(@tmpdir)
+        Dir.mkdir(@tmpdir)
+      end
+      Dir.chdir(@tmpdir)
+      @home_backup = ENV["HOME"]
+      ENV["HOME"] = @tmpdir
+      @default_encoding = [Encoding.default_external, Encoding.default_internal]
+      @stdio_encodings = [STDIN, STDOUT, STDERR].map {|io| [io.external_encoding, io.internal_encoding] }
+      IRB.instance_variable_get(:@CONF).clear
+    end
+
+    def teardown
+      ENV["HOME"] = @home_backup
+      Dir.chdir(@pwd)
+      FileUtils.rm_rf(@tmpdir)
+      EnvUtil.suppress_warning {
+        Encoding.default_external, Encoding.default_internal = *@default_encoding
+        [STDIN, STDOUT, STDERR].zip(@stdio_encodings) do |io, encs|
+          io.set_encoding(*encs)
+        end
+      }
+    end
+
+    def test_irb_info_multiline
+      FileUtils.touch("#{@tmpdir}/.inputrc")
+      FileUtils.touch("#{@tmpdir}/.irbrc")
+      IRB.setup(__FILE__, argv: [])
+      IRB.conf[:USE_MULTILINE] = true
+      IRB.conf[:USE_SINGLELINE] = false
+      IRB.conf[:VERBOSE] = false
+      workspace = IRB::WorkSpace.new(self)
+      irb = IRB::Irb.new(workspace)
+      IRB.conf[:MAIN_CONTEXT] = irb.context
+      expected = %r{
+        Ruby\sversion: .+\n
+        IRB\sversion:\sirb .+\n
+        InputMethod:\sReidlineInputMethod\swith\sReline .+ and .+\n
+        \.irbrc\spath: .+
+      }x
+      assert_match expected, irb.context.main.irb_info.to_s
+    end
+
+    def test_irb_info_singleline
+      FileUtils.touch("#{@tmpdir}/.inputrc")
+      FileUtils.touch("#{@tmpdir}/.irbrc")
+      IRB.setup(__FILE__, argv: [])
+      IRB.conf[:USE_MULTILINE] = false
+      IRB.conf[:USE_SINGLELINE] = true
+      IRB.conf[:VERBOSE] = false
+      workspace = IRB::WorkSpace.new(self)
+      irb = IRB::Irb.new(workspace)
+      IRB.conf[:MAIN_CONTEXT] = irb.context
+      expected = %r{
+        Ruby\sversion: .+\n
+        IRB\sversion:\sirb .+\n
+        InputMethod:\sReadlineInputMethod\swith .+ and .+\n
+        \.irbrc\spath: .+
+      }x
+      assert_match expected, irb.context.main.irb_info.to_s
+    end
+
+    def test_irb_info_multiline_without_rc_files
+      inputrc_backup = ENV["INPUTRC"]
+      ENV["INPUTRC"] = "unknown_inpurc"
+      ext_backup = IRB::IRBRC_EXT
+      IRB.__send__(:remove_const, :IRBRC_EXT)
+      IRB.const_set(:IRBRC_EXT, "unknown_ext")
+      IRB.setup(__FILE__, argv: [])
+      IRB.conf[:USE_MULTILINE] = true
+      IRB.conf[:USE_SINGLELINE] = false
+      IRB.conf[:VERBOSE] = false
+      workspace = IRB::WorkSpace.new(self)
+      irb = IRB::Irb.new(workspace)
+      IRB.conf[:MAIN_CONTEXT] = irb.context
+      expected = %r{
+        Ruby\sversion: .+\n
+        IRB\sversion:\sirb .+\n
+        InputMethod:\sReidlineInputMethod\swith\sReline\s[^ ]+(?!\sand\s.+)\n
+        \z
+      }x
+      assert_match expected, irb.context.main.irb_info.to_s
+    ensure
+      ENV["INPUTRC"] = inputrc_backup
+      IRB.__send__(:remove_const, :IRBRC_EXT)
+      IRB.const_set(:IRBRC_EXT, ext_backup)
+    end
+
+    def test_irb_info_singleline_without_rc_files
+      inputrc_backup = ENV["INPUTRC"]
+      ENV["INPUTRC"] = "unknown_inpurc"
+      ext_backup = IRB::IRBRC_EXT
+      IRB.__send__(:remove_const, :IRBRC_EXT)
+      IRB.const_set(:IRBRC_EXT, "unknown_ext")
+      IRB.setup(__FILE__, argv: [])
+      IRB.conf[:USE_MULTILINE] = false
+      IRB.conf[:USE_SINGLELINE] = true
+      IRB.conf[:VERBOSE] = false
+      workspace = IRB::WorkSpace.new(self)
+      irb = IRB::Irb.new(workspace)
+      IRB.conf[:MAIN_CONTEXT] = irb.context
+      expected = %r{
+        Ruby\sversion: .+\n
+        IRB\sversion:\sirb .+\n
+        InputMethod:\sReadlineInputMethod\swith\s(?~.*\sand\s.+)\n
+        \z
+      }x
+      assert_match expected, irb.context.main.irb_info.to_s
+    ensure
+      ENV["INPUTRC"] = inputrc_backup
+      IRB.__send__(:remove_const, :IRBRC_EXT)
+      IRB.const_set(:IRBRC_EXT, ext_backup)
+    end
+  end
+end
diff --git a/test/irb/test_context.rb b/test/irb/test_context.rb
index d03cc30c78..fa628bba46 100644
--- a/test/irb/test_context.rb
+++ b/test/irb/test_context.rb
@@ -30,6 +30,10 @@ module TestIRB
       def reset
         @line_no = 0
       end
+
+      def winsize
+        [10, 20]
+      end
     end
 
     def setup
@@ -98,6 +102,21 @@ module TestIRB
       $VERBOSE = verbose
     end
 
+    def test_eval_object_without_inspect_method
+      verbose, $VERBOSE = $VERBOSE, nil
+      input = TestInputMethod.new([
+        "BasicObject.new\n",
+      ])
+      irb = IRB::Irb.new(IRB::WorkSpace.new(Object.new), input)
+      out, err = capture_output do
+        irb.eval_input
+      end
+      assert_empty err
+      assert(/\(Object doesn't support #inspect\)\n(=> )?\n/, out)
+    ensure
+      $VERBOSE = verbose
+    end
+
     def test_default_config
       assert_equal(true, @context.use_colorize?)
     end
@@ -198,6 +217,151 @@ module TestIRB
       assert_equal("", out)
     end
 
+    def test_omit_on_assignment
+      input = TestInputMethod.new([
+        "a = [1] * 100\n",
+        "a\n",
+      ])
+      value = [1] * 100
+      irb = IRB::Irb.new(IRB::WorkSpace.new(Object.new), input)
+      irb.context.return_format = "=> %s\n"
+
+      irb.context.echo = true
+      irb.context.echo_on_assignment = false
+      irb.context.omit_on_assignment = true
+      out, err = capture_io do
+        irb.eval_input
+      end
+      assert_empty err
+      assert_equal("=> #{value.inspect}\n", out)
+
+      input.reset
+      irb.context.echo = true
+      irb.context.echo_on_assignment = true
+      irb.context.omit_on_assignment = true
+      out, err = capture_io do
+        irb.eval_input
+      end
+      assert_empty err
+      assert_equal("=> #{value.inspect[0..(input.winsize.last - 9)]}...\e[0m\n=> #{value.inspect}\n", out)
+
+      input.reset
+      irb.context.echo = true
+      irb.context.echo_on_assignment = true
+      irb.context.omit_on_assignment = false
+      out, err = capture_io do
+        irb.eval_input
+      end
+      assert_empty err
+      assert_equal("=> #{value.inspect}\n=> #{value.inspect}\n", out)
+
+      input.reset
+      irb.context.echo = false
+      irb.context.echo_on_assignment = false
+      irb.context.omit_on_assignment = true
+      out, err = capture_io do
+        irb.eval_input
+      end
+      assert_empty err
+      assert_equal("", out)
+
+      input.reset
+      irb.context.echo = false
+      irb.context.echo_on_assignment = true
+      irb.context.omit_on_assignment = true
+      out, err = capture_io do
+        irb.eval_input
+      end
+      assert_empty err
+      assert_equal("", out)
+
+      input.reset
+      irb.context.echo = false
+      irb.context.echo_on_assignment = true
+      irb.context.omit_on_assignment = false
+      out, err = capture_io do
+        irb.eval_input
+      end
+      assert_empty err
+      assert_equal("", out)
+    end
+
+    def test_omit_multiline_on_assignment
+      input = TestInputMethod.new([
+        "class A; def inspect; ([?* * 1000] * 3).join(%{\\n}); end; end; a = A.new\n",
+        "a\n"
+      ])
+      value = ([?* * 1000] * 3).join(%{\n})
+      value_first_line = (?* * 1000).to_s
+      irb = IRB::Irb.new(IRB::WorkSpace.new(Object.new), input)
+      irb.context.return_format = "=> %s\n"
+
+      irb.context.echo = true
+      irb.context.echo_on_assignment = false
+      irb.context.omit_on_assignment = true
+      out, err = capture_io do
+        irb.eval_input
+      end
+      assert_empty err
+      assert_equal("=> \n#{value}\n", out)
+      irb.context.evaluate('A.remove_method(:inspect)', 0)
+
+      input.reset
+      irb.context.echo = true
+      irb.context.echo_on_assignment = true
+      irb.context.omit_on_assignment = true
+      out, err = capture_io do
+        irb.eval_input
+      end
+      assert_empty err
+      assert_equal("=> #{value_first_line[0..(input.winsize.last - 9)]}...\e[0m\n=> \n#{value}\n", out)
+      irb.context.evaluate('A.remove_method(:inspect)', 0)
+
+      input.reset
+      irb.context.echo = true
+      irb.context.echo_on_assignment = true
+      irb.context.omit_on_assignment = false
+      out, err = capture_io do
+        irb.eval_input
+      end
+      assert_empty err
+      assert_equal("=> \n#{value}\n=> \n#{value}\n", out)
+      irb.context.evaluate('A.remove_method(:inspect)', 0)
+
+      input.reset
+      irb.context.echo = false
+      irb.context.echo_on_assignment = false
+      irb.context.omit_on_assignment = true
+      out, err = capture_io do
+        irb.eval_input
+      end
+      assert_empty err
+      assert_equal("", out)
+      irb.context.evaluate('A.remove_method(:inspect)', 0)
+
+      input.reset
+      irb.context.echo = false
+      irb.context.echo_on_assignment = true
+      irb.context.omit_on_assignment = true
+      out, err = capture_io do
+        irb.eval_input
+      end
+      assert_empty err
+      assert_equal("", out)
+      irb.context.evaluate('A.remove_method(:inspect)', 0)
+
+      input.reset
+      irb.context.echo = false
+      irb.context.echo_on_assignment = true
+      irb.context.omit_on_assignment = false
+      out, err = capture_io do
+        irb.eval_input
+      end
+      assert_empty err
+      assert_equal("", out)
+      irb.context.evaluate('A.remove_method(:inspect)', 0)
+    end
+
     def test_echo_on_assignment_conf
       # Default
       IRB.conf[:ECHO] = nil
@@ -206,22 +370,26 @@ module TestIRB
       irb = IRB::Irb.new(IRB::WorkSpace.new(Object.new), input)
 
       assert(irb.context.echo?, "echo? should be true by default")
-      refute(irb.context.echo_on_assignment?, "echo_on_assignment? should be false by default")
+      assert(irb.context.echo_on_assignment?, "echo_on_assignment? should be true by default")
+      assert(irb.context.omit_on_assignment?, "omit_on_assignment? should be true by default")
 
       # Explicitly set :ECHO to false
       IRB.conf[:ECHO] = false
       irb = IRB::Irb.new(IRB::WorkSpace.new(Object.new), input)
 
       refute(irb.context.echo?, "echo? should be false when IRB.conf[:ECHO] is set to false")
-      refute(irb.context.echo_on_assignment?, "echo_on_assignment? should be false by default")
+      assert(irb.context.echo_on_assignment?, "echo_on_assignment? should be true by default")
+      assert(irb.context.omit_on_assignment?, "omit_on_assignment? should be true by default")
 
       # Explicitly set :ECHO_ON_ASSIGNMENT to true
       IRB.conf[:ECHO] = nil
-      IRB.conf[:ECHO_ON_ASSIGNMENT] = true
+      IRB.conf[:ECHO_ON_ASSIGNMENT] = false
+      IRB.conf[:OMIT_ON_ASSIGNMENT] = false
       irb = IRB::Irb.new(IRB::WorkSpace.new(Object.new), input)
 
       assert(irb.context.echo?, "echo? should be true by default")
-      assert(irb.context.echo_on_assignment?, "echo_on_assignment? should be true when IRB.conf[:ECHO_ON_ASSIGNMENT] is set to true")
+      refute(irb.context.echo_on_assignment?, "echo_on_assignment? should be false when IRB.conf[:ECHO_ON_ASSIGNMENT] is set to false")
+      refute(irb.context.omit_on_assignment?, "omit_on_assignment? should be false when IRB.conf[:OMIT_ON_ASSIGNMENT] is set to false")
     end
 
     def test_multiline_output_on_default_inspector
diff --git a/test/irb/test_history.rb b/test/irb/test_history.rb
new file mode 100644
index 0000000000..3591f88f59
--- /dev/null
+++ b/test/irb/test_history.rb
@@ -0,0 +1,153 @@
+# frozen_string_literal: false
+require 'test/unit'
+require 'irb'
+require 'readline'
+
+module TestIRB
+  class TestHistory < Test::Unit::TestCase
+    def setup
+      IRB.conf[:RC_NAME_GENERATOR] = nil
+    end
+
+    def teardown
+      IRB.conf[:RC_NAME_GENERATOR] = nil
+    end
+
+    def test_history_save_1
+      omit "Skip Editline" if /EditLine/n.match(Readline::VERSION)
+      _result_output, result_history_file = launch_irb_with_irbrc_and_irb_history(<<~IRBRC, <<~IRB_HISTORY) do |stdin|
+        IRB.conf[:USE_READLINE] = true
+        IRB.conf[:SAVE_HISTORY] = 1
+        IRB.conf[:USE_READLINE] = true
+      IRBRC
+        1
+        2
+        3
+        4
+      IRB_HISTORY
+        stdin.write("5\nexit\n")
+      end
+
+      assert_equal(<<~HISTORY_FILE, result_history_file)
+        exit
+      HISTORY_FILE
+    end
+
+    def test_history_save_100
+      omit "Skip Editline" if /EditLine/n.match(Readline::VERSION)
+      _result_output, result_history_file = launch_irb_with_irbrc_and_irb_history(<<~IRBRC, <<~IRB_HISTORY) do |stdin|
+        IRB.conf[:USE_READLINE] = true
+        IRB.conf[:SAVE_HISTORY] = 100
+        IRB.conf[:USE_READLINE] = true
+      IRBRC
+        1
+        2
+        3
+        4
+      IRB_HISTORY
+        stdin.write("5\nexit\n")
+      end
+
+      assert_equal(<<~HISTORY_FILE, result_history_file)
+        1
+        2
+        3
+        4
+        5
+        exit
+      HISTORY_FILE
+    end
+
+    def test_history_save_bignum
+      omit "Skip Editline" if /EditLine/n.match(Readline::VERSION)
+      _result_output, result_history_file = launch_irb_with_irbrc_and_irb_history(<<~IRBRC, <<~IRB_HISTORY) do |stdin|
+        IRB.conf[:USE_READLINE] = true
+        IRB.conf[:SAVE_HISTORY] = 10 ** 19
+        IRB.conf[:USE_READLINE] = true
+      IRBRC
+        1
+        2
+        3
+        4
+      IRB_HISTORY
+        stdin.write("5\nexit\n")
+      end
+
+      assert_equal(<<~HISTORY_FILE, result_history_file)
+        1
+        2
+        3
+        4
+        5
+        exit
+      HISTORY_FILE
+    end
+
+    def test_history_save_minus_as_infinity
+      omit "Skip Editline" if /EditLine/n.match(Readline::VERSION)
+      _result_output, result_history_file = launch_irb_with_irbrc_and_irb_history(<<~IRBRC, <<~IRB_HISTORY) do |stdin|
+        IRB.conf[:USE_READLINE] = true
+        IRB.conf[:SAVE_HISTORY] = -1 # infinity
+        IRB.conf[:USE_READLINE] = true
+      IRBRC
+        1
+        2
+        3
+        4
+      IRB_HISTORY
+        stdin.write("5\nexit\n")
+      end
+
+      assert_equal(<<~HISTORY_FILE, result_history_file)
+        1
+        2
+        3
+        4
+        5
+        exit
+      HISTORY_FILE
+    end
+
+    private
+
+    def launch_irb_with_irbrc_and_irb_history(irbrc, irb_history)
+      result = nil
+      result_history = nil
+      backup_irbrc = ENV.delete("IRBRC")
+      backup_home = ENV["HOME"]
+      Dir.mktmpdir("test_irb_history_#{$$}") do |tmpdir|
+        ENV["HOME"] = tmpdir
+        open(IRB.rc_file, "w") do |f|
+          f.write(irbrc)
+        end
+        open(IRB.rc_file("_history"), "w") do |f|
+          f.write(irb_history)
+        end
+
+        with_temp_stdio do |stdin, stdout|
+          yield(stdin, stdout)
+          stdin.close
+          stdout.flush
+          system('ruby', '-Ilib', '-Itest', '-W0', '-rirb', '-e', 'IRB.start(__FILE__)', in: stdin.path, out: stdout.path)
+          result = stdout.read
+          stdout.close
+        end
+        open(IRB.rc_file("_history"), "r") do |f|
+          result_history = f.read
+        end
+      end
+      [result, result_history]
+    ensure
+      ENV["HOME"] = backup_home
+      ENV["IRBRC"] = backup_irbrc
+    end
+
+    def with_temp_stdio
+      Tempfile.create("test_readline_stdin") do |stdin|
+        Tempfile.create("test_readline_stdout") do |stdout|
+          yield stdin, stdout
+        end
+      end
+    end
+  end
+end if not RUBY_PLATFORM.match?(/solaris|mswin|mingw/i)
diff --git a/test/irb/test_ruby_lex.rb b/test/irb/test_ruby_lex.rb
index dd5a1f7ca5..14b43f5718 100644
--- a/test/irb/test_ruby_lex.rb
+++ b/test/irb/test_ruby_lex.rb
@@ -5,7 +5,7 @@ require 'ostruct'
 
 module TestIRB
   class TestRubyLex < Test::Unit::TestCase
-    Row = Struct.new(:content, :current_line_spaces, :new_line_spaces)
+    Row = Struct.new(:content, :current_line_spaces, :new_line_spaces, :nesting_level)
 
     class MockIO
       def initialize(params, &assertion)
@@ -34,6 +34,15 @@ module TestIRB
       ruby_lex.set_auto_indent(context)
     end
 
+    def assert_nesting_level(lines, expected)
+      ruby_lex = RubyLex.new()
+      io = proc{ lines.join("\n") }
+      ruby_lex.set_input(io, io)
+      ruby_lex.lex
+      error_message = "Calculated the wrong number of nesting level for:\n #{lines.join("\n")}"
+      assert_equal(expected, ruby_lex.instance_variable_get(:@indent), error_message)
+    end
+
     def test_auto_indent
       input_with_correct_indents = [
         Row.new(%q(def each_top_level_statement), nil, 2),
@@ -126,5 +135,130 @@ module TestIRB
         assert_indenting(lines, row.new_line_spaces, true)
       end
     end
+
+    def test_incomplete_coding_magic_comment
+      input_with_correct_indents = [
+        Row.new(%q(#coding:u), nil, 0),
+      ]
+
+      lines = []
+      input_with_correct_indents.each do |row|
+        lines << row.content
+        assert_indenting(lines, row.current_line_spaces, false)
+        assert_indenting(lines, row.new_line_spaces, true)
+      end
+    end
+
+    def test_incomplete_encoding_magic_comment
+      input_with_correct_indents = [
+        Row.new(%q(#encoding:u), nil, 0),
+      ]
+
+      lines = []
+      input_with_correct_indents.each do |row|
+        lines << row.content
+        assert_indenting(lines, row.current_line_spaces, false)
+        assert_indenting(lines, row.new_line_spaces, true)
+      end
+    end
+
+    def test_incomplete_emacs_coding_magic_comment
+      input_with_correct_indents = [
+        Row.new(%q(# -*- coding: u), nil, 0),
+      ]
+
+      lines = []
+      input_with_correct_indents.each do |row|
+        lines << row.content
+        assert_indenting(lines, row.current_line_spaces, false)
+        assert_indenting(lines, row.new_line_spaces, true)
+      end
+    end
+
+    def test_incomplete_vim_coding_magic_comment
+      input_with_correct_indents = [
+        Row.new(%q(# vim:set fileencoding=u), nil, 0),
+      ]
+
+      lines = []
+      input_with_correct_indents.each do |row|
+        lines << row.content
+        assert_indenting(lines, row.current_line_spaces, false)
+        assert_indenting(lines, row.new_line_spaces, true)
+      end
+    end
+
+    def test_mixed_rescue
+      input_with_correct_indents = [
+        Row.new(%q(def m), nil, 2),
+        Row.new(%q(  begin), nil, 4),
+        Row.new(%q(    begin), nil, 6),
+        Row.new(%q(      x = a rescue 4), nil, 6),
+        Row.new(%q(      y = [(a rescue 5)]), nil, 6),
+        Row.new(%q(      [x, y]), nil, 6),
+        Row.new(%q(    rescue => e), 4, 6),
+        Row.new(%q(      raise e rescue 8), nil, 6),
+        Row.new(%q(    end), 4, 4),
+        Row.new(%q(  rescue), 2, 4),
+        Row.new(%q(    raise rescue 11), nil, 4),
+        Row.new(%q(  end), 2, 2),
+        Row.new(%q(rescue => e), 0, 2),
+        Row.new(%q(  raise e rescue 14), nil, 2),
+        Row.new(%q(end), 0, 0),
+      ]
+
+      lines = []
+      input_with_correct_indents.each do |row|
+        lines << row.content
+        assert_indenting(lines, row.current_line_spaces, false)
+        assert_indenting(lines, row.new_line_spaces, true)
+      end
+    end
+
+    def test_oneliner_method_definition
+      input_with_correct_indents = [
+        Row.new(%q(class A), nil, 2),
+        Row.new(%q(  def foo0), nil, 4),
+        Row.new(%q(    3), nil, 4),
+        Row.new(%q(  end), 2, 2),
+        Row.new(%q(  def foo1()), nil, 4),
+        Row.new(%q(    3), nil, 4),
+        Row.new(%q(  end), 2, 2),
+        Row.new(%q(  def foo2(a, b)), nil, 4),
+        Row.new(%q(    a + b), nil, 4),
+        Row.new(%q(  end), 2, 2),
+        Row.new(%q(  def foo3 a, b), nil, 4),
+        Row.new(%q(    a + b), nil, 4),
+        Row.new(%q(  end), 2, 2),
+        Row.new(%q(  def bar0() = 3), nil, 2),
+        Row.new(%q(  def bar1(a) = a), nil, 2),
+        Row.new(%q(  def bar2(a, b) = a + b), nil, 2),
+        Row.new(%q(end), 0, 0),
+      ]
+
+      lines = []
+      input_with_correct_indents.each do |row|
+        lines << row.content
+        assert_indenting(lines, row.current_line_spaces, false)
+        assert_indenting(lines, row.new_line_spaces, true)
+      end
+    end
+
+    def test_tlambda
+      input_with_correct_indents = [
+        Row.new(%q(if true), nil, 2, 1),
+        Row.new(%q(  -> {), nil, 4, 2),
+        Row.new(%q(  }), 2, 2, 1),
+        Row.new(%q(end), 0, 0, 0),
+      ]
+
+      lines = []
+      input_with_correct_indents.each do |row|
+        lines << row.content
+        assert_indenting(lines, row.current_line_spaces, false)
+        assert_indenting(lines, row.new_line_spaces, true)
+        assert_nesting_level(lines, row.nesting_level)
+      end
+    end
   end
 end
diff --git a/test/irb/test_workspace.rb b/test/irb/test_workspace.rb
index 992cdd4516..15c77315a8 100644
--- a/test/irb/test_workspace.rb
+++ b/test/irb/test_workspace.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: false
 require 'test/unit'
 require 'tempfile'
+require 'rubygems'
 require 'irb'
 require 'irb/workspace'
 require 'irb/color'