[bug#39745] [PATCH 4/7] gnu: java-openjfx-swing: Add new variable.

[Leo Famulari]

On Sat, Feb 22, 2020 at 09:17:52PM +0100, Alexey Abramov wrote:
> * gnu/packages/java.scm (java-openjfx-build): Add patch to the base package.
> * 
> gnu/packages/patches/java-openjfx-build-swing-compile-JFXPanel-with-JDK-8.patch:
>  Fix swing compilation for jdk8.

This commit adds the patch file but also makes a new package
java-openjfx-swing. Adding the patch to java-openjfx-build and adding
the new package should be done in separate commits.

Also remember to add the patch to 'gnu/local.mk'.

> +From 173e65937d9e76872df51f7ba39c9d58986dc38f Mon Sep 17 00:00:00 2001
> +From: Alexey Abramov <address@hidden>
> +Date: Fri, 3 Jan 2020 01:17:45 +0100
> +Subject: [PATCH] java-openjfx-build: Cannot compile JFXPanel with JDK 8
> +
> +For more info please see https://bugs.openjdk.java.net/browse/JDK-8149967

This link is great but please add a brief summary of why we need the
patch and what it does (one or two sentences is enough).