[ruby-core:104397] [Ruby master Bug#12261] Windows: File.dirname with 2+ / or 2+ \\ will return // or \\\\

Issue #12261 has been updated by jeremyevans0 (Jeremy Evans).

Assignee set to usa (Usaku NAKAMURA)
Status changed from Open to Assigned

I'm not sure whether this behavior was originally expected, but I think changing it at this point isn't worth the backwards compatibility breakage.  For example, consider the following:

```ruby
dir = File.dirname(string) # string could be '/////'
File.read(File.join(dir, 'server', 'share'))
```

If you change the behavior of `File.dirname` from returning `//` to returning `/`, you change which file is read. In general, that's probably going to result an an Errno::ENOENT exception, but in the pathological case, it results in an unintended file being read.

@usa Can you please determine whether this is a bug?

----------------------------------------
Bug #12261: Windows: File.dirname with 2+ / or 2+ \\ will return // or \\\\
https://bugs.ruby-lang.org/issues/12261#change-92638

* Author: enebo (Thomas Enebo)
* Status: Assigned
* Priority: Normal
* Assignee: usa (Usaku NAKAMURA)
* Backport: 2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: UNKNOWN
----------------------------------------
I am working through some File.dirname issues on JRuby and I saw a ruby/spec covering this behavior on windows:

`File.dirname('/////').should == '//'`

Same result if backslashes are used.  Is there a reason for this result?  It does not seem useful to me but I am not much of a windows user.  I would think in this case it would be '/' since I don't see how this is useful for UNC paths in Ruby?  If someone could explain it then I will document this at least in JRuby source code :)

So far all versions of MRI seem to have this behavior.





-- 
https://bugs.ruby-lang.org/

Unsubscribe: <mailto:[e-mail]?subject=unsubscribe>
<http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>