Don't prepend current path to symlink targets

It's confusing, and `ls` doesn't do this either. We're not prepending
the current path to all of the directory entries, and the user is going
to interpret the symlink target as relative to the directory containing
the symlink.

src/fs/file.rs

@@ -169,28 +169,32 @@ impl<'dir> File<'dir> {
             Err(e)    => return FileTarget::Err(e),
         };
 
-        let target_path = match self.dir {
-            Some(dir)  => dir.join(&*path),
-            None       => path
+        let (metadata, ext) = {
+            let target_path_ = match self.dir {
+                Some(dir) if dir.path != Path::new(".") => Some(dir.join(&*path)),
+                _                                       => None
+            };
+            let target_path = target_path_.as_ref().unwrap_or(&path);
+            // Use plain `metadata` instead of `symlink_metadata` - we *want* to follow links.
+            (fs::metadata(&target_path), ext(&target_path))
         };
 
-        let filename = match target_path.components().next_back() {
+        let filename = match path.components().next_back() {
             Some(comp) => comp.as_os_str().to_string_lossy().to_string(),
             None       => String::new(),
         };
 
-        // Use plain `metadata` instead of `symlink_metadata` - we *want* to follow links.
-        if let Ok(metadata) = fs::metadata(&target_path) {
+        if let Ok(metadata) = metadata {
             FileTarget::Ok(File {
-                path:      target_path.to_path_buf(),
+                path:      path,
                 dir:       self.dir,
                 metadata:  metadata,
-                ext:       ext(&target_path),
+                ext:       ext,
                 name:      filename,
             })
         }
         else {
-            FileTarget::Broken(target_path)
+            FileTarget::Broken(path)
         }
     }
 

xtests/links_1

-broken -> /testcases/links/nowhere
+broken -> nowhere
 forbidden -> /proc/1/root
 root -> /
 usr -> /usr

xtests/links_T

 /testcases/links
-├── broken -> /testcases/links/nowhere
+├── broken -> nowhere
 │  └── <No such file or directory (os error 2)>
 ├── forbidden -> /proc/1/root
 │  └── <Permission denied (os error 13)>