Add a test for dialog at right edge

Author: aycabta

test/reline/yamatanooroti/test_rendering.rb

@@ -854,6 +854,25 @@ def test_simple_dialog
       EOC
     end
 
+    def test_simple_dialog_at_right_edge
+      start_terminal(20, 40, %W{ruby -I#{@pwd}/lib #{@pwd}/test/reline/yamatanooroti/multiline_repl --dialog simple}, startup_message: 'Multiline REPL.')
+      write('a')
+      write('b')
+      write('c')
+      write("\C-h")
+      close
+      assert_screen(<<~'EOC')
+        Multiline REPL.
+        prompt> ab
+            Ruby is...
+            A dynamic, open source programming
+            language with a focus on simplicity
+            and productivity. It has an elegant
+            syntax that is natural to read and
+            easy to write.
+      EOC
+    end
+
     def test_simple_dialog_with_scroll_key
       start_terminal(20, 50, %W{ruby -I#{@pwd}/lib #{@pwd}/test/reline/yamatanooroti/multiline_repl --dialog long,scrollkey}, startup_message: 'Multiline REPL.')
       write('a')