feat: one store directory per checkout

tests/link_store.rs

@@ -260,3 +260,25 @@ fn distinct_remotes_do_not_share_one_store_directory() {
     // the ordinary remote keeps the path it already had
     assert!(plain.contains("/a/my_api"), "{plain}");
 }
+
+#[test]
+fn two_checkouts_of_one_remote_keep_their_own_files() {
+    let case = Case::new("clones");
+    let second = case.second_checkout();
+    case.write(".env", b"FIRST\n");
+    second.write(".env", b"SECOND\n");
+
+    case.ahab(&["link", "add", ".env"]).ok();
+    // no collision, and no --force needed
+    second.ahab(&["link", "add", ".env"]).ok();
+
+    assert_ne!(case.store, second.store);
+    assert_eq!(fs::read(case.path(".env")).unwrap(), b"FIRST\n");
+    assert_eq!(fs::read(second.path(".env")).unwrap(), b"SECOND\n");
+
+    // one restoring leaves the other linked
+    case.ahab(&["link", "restore", "--all"]).ok();
+    assert!(second.is_symlink(".env"));
+    assert_eq!(fs::read(second.path(".env")).unwrap(), b"SECOND\n");
+    second.ahab(&["link", "list"]).ok().says("linked:    .env");
+}