[ruby/reline] Fix: line longer than terminal width breaks rendering

(https://github.com/ruby/reline/pull/516)

https://github.com/ruby/reline/commit/ae5f9b87ab

lib/reline/line_editor.rb

@@ -972,6 +972,7 @@ class Reline::LineEditor
       prev_line_prompt = @prompt_proc ? prompt_list[@line_index - 1] : prompt
       prev_line_prompt_width = @prompt_proc ? calculate_width(prev_line_prompt, true) : prompt_width
       prev_line = modify_lines(lines)[@line_index - 1]
+      move_cursor_up(@started_from)
       render_partial(prev_line_prompt, prev_line_prompt_width, prev_line, @first_line_started_from + @started_from, with_control: false)
       scroll_down(1)
       render_partial(prompt, prompt_width, @line, @first_line_started_from + @started_from + 1, with_control: false)

test/reline/yamatanooroti/test_rendering.rb

@@ -281,6 +281,23 @@ begin
       EOC
     end
 
+    def test_multiline_add_new_line_and_autowrap
+      start_terminal(10, 20, %W{ruby -I#{@pwd}/lib #{@pwd}/test/reline/yamatanooroti/multiline_repl}, startup_message: 'Multiline REPL.')
+      write("def aaaaaaaaaa")
+      write("\n")
+      write("  bbbbbbbbbbbb")
+      write("\n")
+      close
+      assert_screen(<<~EOC)
+        Multiline REPL.
+        prompt> def aaaaaaaa
+        aa
+        prompt>   bbbbbbbbbb
+        bb
+        prompt>
+      EOC
+    end
+
     def test_clear
       start_terminal(10, 15, %W{ruby -I#{@pwd}/lib #{@pwd}/test/reline/yamatanooroti/multiline_repl}, startup_message: 'Multiline REPL.')
       write("3\C-l")