From bd746e515145e288f7651e150a68984e9ec02ba1 Mon Sep 17 00:00:00 2001 From: Kovid Goyal Date: Fri, 23 Apr 2021 15:48:47 +0530 Subject: [PATCH] Add a note about what happens when no scrollback lines are present --- docs/protocol-extensions.rst | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/docs/protocol-extensions.rst b/docs/protocol-extensions.rst index 5f41ee3ed..976fec3d7 100644 --- a/docs/protocol-extensions.rst +++ b/docs/protocol-extensions.rst @@ -172,7 +172,10 @@ instead of being blank. The motivation for this is that many modern shells will show completions in a block of lines under the cursor, this causes some of the on-screen text to be lost even after the completion is completed, because it has scrolled off -screen. This escape code allows that text to be restored. +screen. This escape code allows that text to be restored. If the scrollback +buffer is empty or there is no scrollback buffer, such as for the alternate +screen, then the newly inserted lines must be empty, just as with the original +``SD`` escape code. The syntax of the escape code is identical to that of ``SD`` except that it has a trailing ``+`` modifier. This is legal under the `ECMA 48 standard