1. Express desired path.join behavior in tests.
2. Update fs.realpath to reflect new path.join behavior
3. Update url.resolve() to use new path.join behavior.
Any path.join or path.normalize that starts with a / will not go "above" that after normalization. This is important because /../foo is almost *always* some sort of error, and doesn't match the corollary in sh: `cd $p; pwd`
At the worse, this can be a vector for exploits, since a static file server might do path.join(docroot, path.normalize("/"+req)) to get the file. If the normalized request path could be something like "/../../../etc/passwd" then bad things could happen.
Before there was this comment:
Can't strip trailing slashes since module.js incorrectly
thinks dirname('/a/b/') should yield '/a/b' instead of '/a'.
But now, such thinking is corrected.
Previously path.dirname('/tmp') incorrectly returned '.'.
Unfortunately module.js incorrectly thinks dirname('/a/b/') should
yield '/a/b', so I can't strip trailing slashes yet. Once module.js
is fixed, then the commented-out code should be activated and a test
written for it.
