There is a Null pointer exception, when the “Path to folder point” to a directory which doesn’t exists

Console output (if directory doesn’t exists)

Started by user anonymous
Building remotely on dem6894 (RanorexTestPC) in workspace d:\JenkinsSlaveRoot\workspace\Debug
FATAL: null
java.lang.NullPointerException
at hpi.CopyDataToWorkspacePlugin.saveNames(CopyDataToWorkspacePlugin.java:164)
at hpi.CopyDataToWorkspacePlugin.setUp(CopyDataToWorkspacePlugin.java:92)
at hudson.model.Build$BuildExecution.doRun(Build.java:154)
at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:536)
at hudson.model.Run.execute(Run.java:1718)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
at hudson.model.ResourceController.execute(ResourceController.java:89)
at hudson.model.Executor.run(Executor.java:240)

Console output (if directory does exists)

Started by user anonymous
Building remotely on dem6894 (RanorexTestPC) in workspace d:\JenkinsSlaveRoot\workspace\Debug
Collecting metadata...
Metadata collection done.
Finished: SUCCESS

I traced to problem back to line 164 of Code.java

- this.copiedFiles = new String[children.size()];
+ this.copiedFiles = new String[children != null ? children.size() : 0];

It is probably a good idea to show some kind of error message to the user, that the configured folder does not exist, but I do not know how to do that.