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)

src/popupwin.c

@@ -375,22 +375,36 @@ popup_is_in_scrollbar(win_T *wp, int row, int col)
     void
 popup_handle_scrollbar_click(win_T *wp, int row, int col)
 {
-    int	    height = popup_height(wp);
-    int	    old_topline = wp->w_topline;
-
     if (popup_is_in_scrollbar(wp, row, col))
     {
+	int	    height = popup_height(wp);
+	int	    new_topline = wp->w_topline;
+
 	if (row >= height / 2)
 	{
 	    // Click in lower half, scroll down.
 	    if (wp->w_topline < wp->w_buffer->b_ml.ml_line_count)
-		++wp->w_topline;
+		++new_topline;
 	}
 	else if (wp->w_topline > 1)
 	    // click on upper half, scroll up.
-	    --wp->w_topline;
+	    --new_topline;
-	if (wp->w_topline != old_topline)
+	if (new_topline != wp->w_topline)
 	{
+	    set_topline(wp, new_topline);
+	    if (wp == curwin)
+	    {
+		if (wp->w_cursor.lnum < wp->w_topline)
+		{
+		    wp->w_cursor.lnum = wp->w_topline;
+		    check_cursor();
+		}
+		else if (wp->w_cursor.lnum >= wp->w_botline)
+		{
+		    wp->w_cursor.lnum = wp->w_botline - 1;
+		    check_cursor();
+		}
+	    }
 	    popup_set_firstline(wp);
 	    redraw_win_later(wp, NOT_VALID);
 	}
@@ -1419,8 +1433,9 @@ popup_adjust_position(win_T *wp)
     wp->w_has_scrollbar = wp->w_want_scrollbar
 	   && (wp->w_topline > 1 || lnum <= wp->w_buffer->b_ml.ml_line_count);
 #ifdef FEAT_TERMINAL
-    if (wp->w_buffer->b_term != NULL)
+    if (wp->w_buffer->b_term != NULL && !term_is_finished(wp->w_buffer))
-	// Terminal window never has a scrollbar, adjusts to window height.
+	// Terminal window with running job never has a scrollbar, adjusts to
+	// window height.
 	wp->w_has_scrollbar = FALSE;
 #endif
     maxwidth_no_scrollbar = maxwidth;
@@ -1587,7 +1602,7 @@ popup_adjust_position(win_T *wp)
 	// add a scrollbar.
 	wp->w_height = Rows - wp->w_winrow - extra_height;
 #ifdef FEAT_TERMINAL
-	if (wp->w_buffer->b_term == NULL)
+	if (wp->w_buffer->b_term == NULL || term_is_finished(wp->w_buffer))
 #endif
 	{
 	    wp->w_has_scrollbar = TRUE;

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| 

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|%| 

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| 

src/testdir/test_popupwin.vim

@@ -2856,7 +2856,7 @@ func Test_popupwin_terminal_buffer()
   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 @@ func Test_popupwin_terminal_buffer()
   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()

src/version.c

@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    5038,
 /**/
     5037,
 /**/