From 07bdd6049b6d190de69419cc9be2ac49d3a08e0f Mon Sep 17 00:00:00 2001
From: rubenwardy <rw@rubenwardy.com>
Date: Sun, 29 Sep 2019 12:40:59 +0100
Subject: [PATCH] Fix error message caused by adding new parameter to
 background (#8922)

Adds background9[] element to keep backwards compatibility in formspec prepends.
---
 doc/lua_api.txt             | 2 +-
 src/gui/guiFormSpecMenu.cpp | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index cefc53569..b4cf65e54 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -2114,7 +2114,7 @@ Elements
 * If `auto_clip` is `true`, the background is clipped to the formspec size
   (`x` and `y` are used as offset values, `w` and `h` are ignored)
 
-### `background[<X>,<Y>;<W>,<H>;<texture name>;<auto_clip>;<middle>]`
+### `background9[<X>,<Y>;<W>,<H>;<texture name>;<auto_clip>;<middle>]`
 
 * 9-sliced background. See https://en.wikipedia.org/wiki/9-slice_scaling
 * Middle is a rect which defines the middle of the 9-slice.
diff --git a/src/gui/guiFormSpecMenu.cpp b/src/gui/guiFormSpecMenu.cpp
index 390c81bc1..ebcc6b67e 100644
--- a/src/gui/guiFormSpecMenu.cpp
+++ b/src/gui/guiFormSpecMenu.cpp
@@ -2231,8 +2231,8 @@ void GUIFormSpecMenu::parseElement(parserData* data, const std::string &element)
 		return;
 	}
 
-	if (type == "background") {
-		parseBackground(data,description);
+	if (type == "background" || type == "background9") {
+		parseBackground(data, description);
 		return;
 	}