Bug#960630: ant: CVE-2020-1945

[Emmanuel Bourg]

Ant 1.10.8 adds a convenience property to change the temporary
directory. It was already possible to change it in prior versions with:

   ANT_OPTS=-Djava.io.tmpdir=~/temp ant jar

Now it's possible to use:

   ant jar -Dant.tmpdir=~/temp

Or by setting the ant.tmpdir property inside the Ant build.xml file.

Since it requires an action from the user and the issue is already
avoidable I'm tempted to think a backport to stable isn't important.

Emmanuel Bourg