patch 8.2.0791: a second popup window with terminal causes trouble
Problem: A second popup window with terminal causes trouble.
Solution: Disallow opening a second terminal-popup window. (closes #6101,
closes #6103) Avoid defaulting to an invalid line number.
diff --git a/runtime/doc/popup.txt b/runtime/doc/popup.txt
index 5950c47..fdf28a5 100644
--- a/runtime/doc/popup.txt
+++ b/runtime/doc/popup.txt
@@ -150,7 +150,7 @@
- When the job ends, the popup window closes.
- The popup window can be closed with `popup_close()`, the terminal buffer
then becomes hidden.
-- It is not possible to enter Terminal-Normal mode.
+- It is not possible to open a second popup window with a terminal. *E861*
- The default Pmenu color is only used for the border and padding. To change
the color of the terminal itself set the Terminal highlight group before
creating the terminal. Setting 'wincolor' later can work but requires the