cd and ls crash when passed a non-directory link

Uh oh! You've found an error in Core.
This happened while running your code, so you may be able to find a workaround, but is ultimately an issue in Core.
The following code caused the error:
ls('file.zip')
on or around Interpreter:1.
Please report this to the developers, and be sure to include the version numbers:
Server version: SHELL;
MethodScript version: 3.3.4;
Loaded extensions and versions:
Core (3.3.4)
Here's the stacktrace:
java.lang.NullPointerException
at com.laytonsmith.core.functions.Cmdline$ls.exec(Cmdline.java:1699)
at com.laytonsmith.core.Script.eval(Script.java:409)
at com.laytonsmith.core.MethodScriptCompiler.execute(MethodScriptCompiler.java:2818)
at com.laytonsmith.tools.Interpreter$4.run(Interpreter.java:832)
at java.lang.Thread.run(Thread.java:748)

Uh oh! You've found an error in Core.
This happened while running your code, so you may be able to find a workaround, but is ultimately an issue in Core.
The following code caused the error:
cd('file.zip')
on or around Interpreter:1.
Please report this to the developers, and be sure to include the version numbers:
Server version: SHELL;
MethodScript version: 3.3.4;
Loaded extensions and versions:
Core (3.3.4)
Here's the stacktrace:
java.lang.IllegalArgumentException: File provided to SetRootFolder must be a folder, not a file. (.\Downloads\2656-netstat-ipv6.PID.zip was found.)
at com.laytonsmith.core.environments.GlobalEnv.SetRootFolder(GlobalEnv.java:209)
at com.laytonsmith.core.functions.Cmdline$cd.exec(Cmdline.java:1648)
at com.laytonsmith.core.Script.eval(Script.java:409)
at com.laytonsmith.core.MethodScriptCompiler.execute(MethodScriptCompiler.java:2818)
at com.laytonsmith.tools.Interpreter$4.run(Interpreter.java:832)
at java.lang.Thread.run(Thread.java:748)