Escape dots in clean_path()'s regexes

[justinsteven]

clean_path()'s regexes have unescaped dots, causing unintended over-cleaning.

Before patch:

irb(main):003:0> ::Rex::FileUtils::clean_path('a/b/../c')                                                                                                                                                                                                                                   
=> "a/b/c"

This is good

irb(main):004:0> ::Rex::FileUtils::clean_path('a/b/ZZ/c')                                                                                                                                                                                                                                   
=> "a/b/c"

This is bad

Post-patch:

irb(main):002:0> ::Rex::FileUtils::clean_path('a/b/../c')
=> "a/b/c"
irb(main):003:0> ::Rex::FileUtils::clean_path('a/b/ZZ/c')
=> "a/b/ZZ/c"
irb(main):004:0> ::Rex::FileUtils::clean_path('a/b/..\\c')                                                                                                                                                                                                                                  
=> "a/b/c"
irb(main):005:0> ::Rex::FileUtils::clean_path('../a/b/..\\c')                                                                                                                                                                                                                               
=> "a/b/c"
irb(main):006:0> ::Rex::FileUtils::clean_path('..\\a/b/..\\c')                                                                                                                                                                                                                              
=> "a/b/c"

[busterb]

Thanks @justinsteven , those unescaped dots definitely look like an oversight to me.

[pbarry-r7]

Agreed, escaped dots FTW w.r.t. regex. :+1:

[busterb]

I'm going to suggest we move the examples in the PR description into spec/rex/file_spec.rb

[busterb]

Thanks @pbarry-r7

[pbarry-r7]

Release Notes

This patch ensures the Rex clean_path() logic doesn't unexpectedly remove valid directory names from the path being "cleaned".

[pbarry-r7]

Thanks for the fix, @justinsteven!