patch 8.2.0328: no redraw when leaving term-normal mode in popup terminal

Problem:    No redraw when leaving terminal-normal mode in a terminal popup
            window.
Solution:   Redraw the popup window. (closes #5708)
diff --git a/src/testdir/test_terminal.vim b/src/testdir/test_terminal.vim
index fb717f6..e2d7595 100644
--- a/src/testdir/test_terminal.vim
+++ b/src/testdir/test_terminal.vim
@@ -2382,8 +2382,16 @@
 
   call term_sendkeys(buf, "\<C-W>:call ReopenPopup()\<CR>")
   call VerifyScreenDump(buf, 'Test_terminal_popup_6', {})
-  call term_wait(buf, 100)
 
+  " Go to terminal-Normal mode and visually select text.
+  call term_sendkeys(buf, "\<C-W>Ngg/in\<CR>vww")
+  call VerifyScreenDump(buf, 'Test_terminal_popup_7', {})
+
+  " Back to job mode, redraws
+  call term_sendkeys(buf, "A")
+  call VerifyScreenDump(buf, 'Test_terminal_popup_8', {})
+
+  call term_wait(buf, 100)
   call term_sendkeys(buf, ":q\<CR>")
   call term_wait(buf, 100)  " wait for terminal to vanish