Ruby: Potential command injection in `Shell#[]` and `Shell#test`

As Shelltest and Shell use send when transferring to FileTest, private methods etc. can also be called. Therefore, command injection is possible when a crafted value is passed. ruby $ irb irbmain:001:0 ls xy ls: xy: No such file or directory = "" irbmain:002:0 require 'shell' = true irbmain:003:0...