patch 8.2.0984: not using previous window when closing a shell popup window

Problem:    Not using previous window when closing a shell popup window.
Solution:   Use "prevwin" if it was set. (closes #6267)

src/popupwin.c

@@ -2147,6 +2147,19 @@ invoke_popup_callback(win_T *wp, typval_T *result)
     clear_tv(&rettv);
 }
 
+/*
+ * Make "prevwin" the current window, unless it's equal to "wp".
+ * Otherwise make "firstwin" the current window.
+ */
+    static void
+back_to_prevwin(win_T *wp)
+{
+    if (win_valid(prevwin) && wp != prevwin)
+	win_enter(prevwin, FALSE);
+    else
+	win_enter(firstwin, FALSE);
+}
+
 /*
  * Close popup "wp" and invoke any close callback for it.
  */
@@ -2178,10 +2191,8 @@ popup_close_and_callback(win_T *wp, typval_T *arg)
 		    break;
 	    if (owp != NULL)
 		win_enter(owp, FALSE);
-	    else if (win_valid(prevwin) && wp != prevwin)
-		win_enter(prevwin, FALSE);
 	    else
-		win_enter(firstwin, FALSE);
+		back_to_prevwin(wp);
 	}
     }
 #endif
@@ -2583,7 +2594,7 @@ popup_close(int id, int force)
 		    error_for_popup_window();
 		    return FAIL;
 		}
-		win_enter(firstwin, FALSE);
+		back_to_prevwin(wp);
 	    }
 	    if (prev == NULL)
 		first_popupwin = wp->w_next;
@@ -2620,7 +2631,7 @@ popup_close_tabpage(tabpage_T *tp, int id, int force)
 		    error_for_popup_window();
 		    return FAIL;
 		}
-		win_enter(firstwin, FALSE);
+		back_to_prevwin(wp);
 	    }
 	    if (prev == NULL)
 		*root = wp->w_next;

src/testdir/test_popupwin.vim

@@ -2461,6 +2461,23 @@ func Test_popupwin_terminal_buffer()
   call assert_equal(origwin, win_getid())
 endfunc
 
+func Test_popupwin_close_prevwin()
+  CheckFeature terminal
+
+  call assert_equal(1, winnr('$'))
+  split
+  wincmd b
+  call assert_equal(2, winnr())
+  let buf = term_start(&shell, #{hidden: 1})
+  call popup_create(buf, {})
+  call term_wait(buf, 100)
+  call popup_clear(1)
+  call assert_equal(2, winnr())
+
+  quit
+  exe 'bwipe! ' .. buf
+endfunc
+
 func Test_popupwin_with_buffer_and_filter()
   new Xwithfilter
   call setline(1, range(100))

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    984,
 /**/
     983,
 /**/