patch 8.1.1438: some commands cause trouble in a popup window commit https://github.com/vim/vim/commit/815b76bff618c07226653e11f29c4d3c5640b63a Author: Bram Moolenaar <Bram@vim.org> Date: Sat Jun 1 14:15:52 2019 +0200 patch 8.1.1438: some commands cause trouble in a popup window Problem: Some commands cause trouble in a popup window. Solution: Add NOT_IN_POPUP_WINDOW.

--- a/src/popupwin.c
+++ b/src/popupwin.c
@@ -747,4 +747,16 @@ f_popup_getoptions(typval_T *argvars, ty
 # endif
     }
 }
+
+    int
+not_in_popup_window()
+{
+    if (bt_popup(curwin->w_buffer))
+    {
+	emsg(_("E994: Not allowed in a popup window"));
+	return TRUE;
+    }
+    return FALSE;
+}
+
 #endif // FEAT_TEXT_PROP