Bug #90646 for File-Spec: abs2rel returns strange result when $base is not in canonical form

Fri Nov 22 16:39:18 2013 MJD [...] cpan.org - Ticket created

Subject:

abs2rel returns strange result when $base is not in canonical form

File::Spec->abs2rel("/foo/bar/baz", "/foo/bar") returns "baz", as it should. Since "/foo/bar/../bar" is the same , File::Spec->abs2rel("/foo/bar/baz", "/foo/bar/../bar") should mean the same and should return the same. But it returns "../bar/baz". (There might be some argument about what this means if "/foo/bar" is a symlink, say one pointing to "/a/b/c". Then one could argue that "/foo/bar/../bar" resolves to "/a/b/bar" rather than to "/foo/bar". Is that what's happening here? ) I am using File::Spec 3.40. This version number has vanished from the RT "Broken in" menu, because RT.

Wed Nov 27 21:01:57 2013 kwilliams [...] cpan.org - Correspondence added

On Fri Nov 22 16:39:18 2013, MJD wrote: Show quoted text

> File::Spec->abs2rel("/foo/bar/baz", "/foo/bar") returns "baz", as it > should. > Since "/foo/bar/../bar" is the same , File::Spec-

> >abs2rel("/foo/bar/baz", "/foo/bar/../bar") should mean the same and

> should return the same. But it returns "../bar/baz". > > (There might be some argument about what this means if "/foo/bar" is a > symlink, say one pointing to "/a/b/c". Then one could argue that > "/foo/bar/../bar" resolves to "/a/b/bar" rather than to "/foo/bar". > Is that what's happening here? )

I do believe that's what's happening here. I think the behavior you describe is intentional. But I don't think it's abundantly clear from the documentation or method name or anything else. The only thing even tangentially related in the docs is the phrase "No checks against the filesystem are made", implying that there might be a reason to do so, and the only reason I know of is special-case path mappings like symlinks. That stuff is described in the docs for canonpath() though. -Ken

Wed Nov 27 21:01:57 2013 The RT System itself - Status changed from 'new' to 'open'