patch 9.0.0824: crash when using win_move_separator() in other tab pagev9.0.0824

Problem:    Crash when using win_move_separator() in other tab page.
Solution:   Check for valid window in current tab page.
            (closes #11479, closes #11427)

1 files changed, 5 insertions, 0 deletions

diff --git a/src/evalwindow.c b/src/evalwindow.c
index 98c7ff3084..bc5925182e 100644
--- a/src/evalwindow.c
+++ b/src/evalwindow.c
@@ -889,6 +889,11 @@ f_win_move_separator(typval_T *argvars, typval_T *rettv)
     wp = find_win_by_nr_or_id(&argvars[0]);
     if (wp == NULL || win_valid_popup(wp))
 	return;
+    if (!win_valid(wp))
+    {
+	emsg(_(e_cannot_resize_window_in_another_tab_page));
+	return;
+    }
 
     offset = (int)tv_get_number(&argvars[1]);
     win_drag_vsep_line(wp, offset);