[7u-dev] Backport Request: 8068518: IllegalArgumentException in JTree.AccessibleJTree

[Vivi An]

Hello,

Please approve straight backport of bug fix to jdk7u-dev.

Description:
Since TreePath(Object[] path) throws /IllegalArgumentException /in case 
the passed in "path" is null or last element of the array is null. We 
need to make sure the result of TreeModel.getRoot() is not null before 
using it to create TreePath. Fix made adding null guards in related 
areas to avoid /IllegalArgumentException/when creating TreePath/.

/Bug: https://bugs.openjdk.java.net/browse/JDK-8068518
JDK9 Webrev: http://cr.openjdk.java.net/~van/8068518/webrev.01/
JDK9 changeset: http://hg.openjdk.java.net/jdk9/client/jdk/rev/a8efddeaae3d

Thank you

Regards,

Vivi