Support long symbolic/hard link path name by reading the linkpath PAX extension

src/entry.rs

@@ -334,7 +334,18 @@ impl<'a> EntryFields<'a> {
                     Some(Cow::Borrowed(bytes))
                 }
             }
-            None => self.header.link_name_bytes(),
+            None => {
+                if let Some(ref pax) = self.pax_extensions {
+                    let pax = pax_extensions(pax)
+                        .filter_map(|f| f.ok())
+                        .find(|f| f.key_bytes() == b"linkpath")
+                        .map(|f| f.value_bytes());
+                    if let Some(field) = pax {
+                        return Some(Cow::Borrowed(field));
+                    }
+                }
+                self.header.link_name_bytes()
+            }
         }
     }
 

tests/all.rs

@@ -791,6 +791,22 @@ fn pax_path() {
     assert!(first.path().unwrap().ends_with("aaaaaaaaaaaaaaa"));
 }
 
+#[test]
+fn pax_linkpath() {
+    let mut ar = Archive::new(tar!("pax2.tar"));
+    let mut links = t!(ar.entries()).skip(3).take(2);
+
+    let long_symlink = t!(links.next().unwrap());
+    let link_name = long_symlink.link_name().unwrap().unwrap();
+    assert!(link_name.to_str().unwrap().len() > 99);
+    assert!(link_name.ends_with("bbbbbbbbbbbbbbb"));
+
+    let long_hardlink = t!(links.next().unwrap());
+    let link_name = long_hardlink.link_name().unwrap().unwrap();
+    assert!(link_name.to_str().unwrap().len() > 99);
+    assert!(link_name.ends_with("ccccccccccccccc"));
+}
+
 #[test]
 fn long_name_trailing_nul() {
     let mut b = Builder::new(Vec::<u8>::new());