Remove extra items because Reline::HISTORY is a sized queue

lib/reline.rb

@@ -26,6 +26,10 @@ module Reline
   @@ambiguous_width = nil
 
   HISTORY = Class.new(Array) {
+    def initialize(config)
+      @config = config
+    end
+
     def to_s
       'HISTORY'
     end
@@ -45,21 +49,42 @@ module Reline
       super(index, String.new(val, encoding: Encoding::default_external))
     end
 
+    def concat(*val)
+      val.each do |v|
+        push(*v)
+      end
+    end
+
     def push(*val)
+      diff = size + val.size - @config.history_size
+      if diff > 0
+        if diff <= size
+          shift(diff)
+        else
+          diff -= size
+          clear
+          val.shift(diff)
+        end
+      end
       super(*(val.map{ |v| String.new(v, encoding: Encoding::default_external) }))
     end
 
     def <<(val)
+      shift if size + 1 > @config.history_size
       super(String.new(val, encoding: Encoding::default_external))
     end
 
     private def check_index(index)
       index += size if index < 0
-      raise RangeError.new("index=<#{index}>") if index < -@@config.history_size or @@config.history_size < index
+      raise RangeError.new("index=<#{index}>") if index < -@config.history_size or @config.history_size < index
       raise IndexError.new("index=<#{index}>") if index < 0 or size <= index
       index
     end
-  }.new
+
+    private def set_config(config)
+      @config = config
+    end
+  }.new(@@config)
 
   @@completion_append_character = nil
   def self.completion_append_character

test/reline/test_key_actor_emacs.rb

@@ -5,6 +5,7 @@ class Reline::KeyActor::Emacs::Test < Reline::TestCase
     Reline.send(:test_mode)
     @prompt = '> '
     @config = Reline::Config.new # Emacs mode is default
+    Reline::HISTORY.send(:set_config, @config)
     @encoding = (RELINE_TEST_ENCODING rescue Encoding.default_external)
     @line_editor = Reline::LineEditor.new(@config)
     @line_editor.reset(@prompt, @encoding)
@@ -1181,6 +1182,33 @@ class Reline::KeyActor::Emacs::Test < Reline::TestCase
     assert_cursor_max(3)
   end
 
+  def test_larger_histories_than_history_size
+    history_size = @config.history_size
+    @config.history_size = 2
+    Reline::HISTORY.concat(%w{abc 123 AAA})
+    assert_line('')
+    assert_byte_pointer_size('')
+    assert_cursor(0)
+    assert_cursor_max(0)
+    input_keys("\C-p")
+    assert_line('AAA')
+    assert_byte_pointer_size('AAA')
+    assert_cursor(3)
+    assert_cursor_max(3)
+    input_keys("\C-p")
+    assert_line('123')
+    assert_byte_pointer_size('123')
+    assert_cursor(3)
+    assert_cursor_max(3)
+    input_keys("\C-p")
+    assert_line('123')
+    assert_byte_pointer_size('123')
+    assert_cursor(3)
+    assert_cursor_max(3)
+  ensure
+    @config.history_size = history_size
+  end
+
 =begin # TODO: move KeyStroke instance from Reline to LineEditor
   def test_key_delete
     input_keys('ab')