patch 8.2.5038: a finished terminal in a popup window does not show scrollbar

Problem:    A finished terminal in a popup window does not show a scrollbar.
Solution:   Show the scrollbar if the terminal job is finished. (closes
            #10497)
diff --git a/src/testdir/dumps/Test_popupwin_poptermscroll_1.dump b/src/testdir/dumps/Test_popupwin_poptermscroll_1.dump
new file mode 100644
index 0000000..a52b8ad
--- /dev/null
+++ b/src/testdir/dumps/Test_popupwin_poptermscroll_1.dump
@@ -0,0 +1,15 @@
+| +0&#ffffff0@74
+|~+0#4040ff13&| @73
+|~| @14|╔+0#0000001#ffd7ff255|═@40|╗| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255|4|2| @37| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255|4|3| @37| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255|4@1| @37| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255|4|5| @37| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255|4|6| @37| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255|4|7| @37| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255|4|8| @37| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255>4|9| @37| +0#0000000#0000001|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|╚+0#0000001#ffd7ff255|═@40|╝| +0#4040ff13#ffffff0@15
+|~| @73
+|~| @73
+| +0#0000000&@56|5|0|,|1| @9|B|o|t| 
diff --git a/src/testdir/dumps/Test_popupwin_poptermscroll_2.dump b/src/testdir/dumps/Test_popupwin_poptermscroll_2.dump
new file mode 100644
index 0000000..9892397
--- /dev/null
+++ b/src/testdir/dumps/Test_popupwin_poptermscroll_2.dump
@@ -0,0 +1,15 @@
+| +0&#ffffff0@74
+|~+0#4040ff13&| @73
+|~| @14|╔+0#0000001#ffd7ff255|═@40|╗| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255|2|1| @37| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255|2@1| @37| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255|2|3| @37| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255>2|4| @37| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255|2|5| @37| +0#0000000#0000001|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255|2|6| @37| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255|2|7| @37| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|║+0#0000001#ffd7ff255|2|8| @37| +0#0000000#a8a8a8255|║+0#0000001#ffd7ff255| +0#4040ff13#ffffff0@15
+|~| @14|╚+0#0000001#ffd7ff255|═@40|╝| +0#4040ff13#ffffff0@15
+|~| @73
+|~| @73
+| +0#0000000&@56|2|5|,|1| @9|5|0|%| 
diff --git a/src/testdir/dumps/Test_popupwin_poptermscroll_3.dump b/src/testdir/dumps/Test_popupwin_poptermscroll_3.dump
new file mode 100644
index 0000000..deaf8da
--- /dev/null
+++ b/src/testdir/dumps/Test_popupwin_poptermscroll_3.dump
@@ -0,0 +1,15 @@
+> +0&#ffffff0@74
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|:+0#0000000&|q| @54|0|,|0|-|1| @8|A|l@1| 
diff --git a/src/testdir/test_popupwin.vim b/src/testdir/test_popupwin.vim
index f58b159..178f235 100644
--- a/src/testdir/test_popupwin.vim
+++ b/src/testdir/test_popupwin.vim
@@ -2856,7 +2856,7 @@
   call assert_fails('call popup_create(termbuf2, #{})', 'E861:')
   call term_sendkeys(termbuf2, "exit\<CR>")
 
-  " Exiting shell closes popup window
+  " Exiting shell puts popup window in Terminal-Normal mode.
   call feedkeys("exit\<CR>", 'xt')
   " Wait for shell to exit
   call WaitForAssert({-> assert_equal("dead", job_status(term_getjob(termbuf)))})
@@ -2866,6 +2866,42 @@
   call assert_equal(origwin, win_getid())
 endfunc
 
+func Test_popupwin_terminal_scrollbar()
+  CheckFeature terminal
+  CheckScreendump
+  CheckUnix
+
+  call writefile(range(50), 'Xtestfile')
+  let lines =<< trim END
+      vim9script
+
+      term_start(['cat', 'Xtestfile'], {hidden: true})
+	  ->popup_create({
+	      minwidth: 40,
+	      maxwidth: 40,
+	      minheight: 8,
+	      maxheight: 8,
+	      scrollbar: true,
+	      border: []
+	  })
+  END
+  call writefile(lines, 'Xpterm')
+  let buf = RunVimInTerminal('-S Xpterm', #{rows: 15})
+  call VerifyScreenDump(buf, 'Test_popupwin_poptermscroll_1', {})
+
+  " scroll to the middle
+  call term_sendkeys(buf, "50%")
+  call VerifyScreenDump(buf, 'Test_popupwin_poptermscroll_2', {})
+
+  " close the popupwin.
+  call term_sendkeys(buf, ":q\<CR>")
+  call VerifyScreenDump(buf, 'Test_popupwin_poptermscroll_3', {})
+
+  call StopVimInTerminal(buf)
+  call delete('Xtestfile')
+  call delete('Xpterm')
+endfunc
+
 func Test_popupwin_close_prevwin()
   CheckFeature terminal
   call Popupwin_close_prevwin()