header: set entry_size() to 0 for hardlinks

src/header.rs

@@ -298,6 +298,9 @@ impl Header {
     ///
     /// May return an error if the field is corrupted.
     pub fn entry_size(&self) -> io::Result<u64> {
+        if self.entry_type().is_hard_link() {
+            return Ok(0);
+        }
         num_field_wrapper_from(&self.as_old().size).map_err(|err| {
             io::Error::new(
                 err.kind(),

tests/header/mod.rs

@@ -1,12 +1,14 @@
-use std::fs::{self, File};
-use std::io::{self, Write};
-use std::path::Path;
-use std::{iter, mem, thread, time};
-
+use std::{
+    fs::{self, File},
+    io::{self, Write},
+    iter, mem,
+    path::Path,
+    thread, time,
+};
+
+use tar::{EntryType, GnuHeader, Header, HeaderMode};
 use tempfile::Builder;
 
-use tar::{GnuHeader, Header, HeaderMode};
-
 #[test]
 fn default_gnu() {
     let mut h = Header::new_gnu();
@@ -244,3 +246,14 @@ fn byte_slice_conversion() {
     let b_conv: &[u8] = Header::from_byte_slice(h.as_bytes()).as_bytes();
     assert_eq!(b, b_conv);
 }
+
+#[test]
+fn hardlink_entry_size() {
+    let mut h = Header::new_ustar();
+    let p = Path::new("a").join(&vec!["a"; 100].join(""));
+    h.set_entry_type(EntryType::Link);
+    t!(h.set_path(&p));
+    t!(h.set_link_name("foo"));
+    h.set_size(200);
+    assert_eq!(t!(h.entry_size()), 0);
+}