ElyTree: an unborn HEAD is told from a broken one (G-03, in review)

born() takes a HEAD as new only when it names a branch under
refs/heads/ that no ref holds yet; a broken ref, a tag target or any
other state is an error in Git's words. The branch name keeps every
byte. Round 3 is fixed; round 4 waits until 0.1.3 ships.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/ely-tree/src/tests/places.rs

@@ -447,6 +447,27 @@ fn a_new_repository_lists_no_moves_and_no_lfs_files() {
         crate::structure::lfs(&git(), &root).expect("no LFS error"),
         Vec::new()
     );
+    // A new branch whose name ends in a no-break space.
+    let named = committed(&dir.path().join("named"));
+    sh(&named, &["branch", "topic"]);
+    sh(&named, &["checkout", "-q", "--orphan", "topic\u{a0}"]);
+    assert_eq!(crate::recover::reflog(&git(), &named).expect("no reflog error"), Vec::new());
+}
+
+#[test]
+fn a_broken_head_is_an_error_not_an_empty_repository() {
+    let dir = tempfile::tempdir().expect("a temp dir");
+    let root = committed(dir.path());
+    let branch = sh(&root, &["symbolic-ref", "--short", "HEAD"]).trim().to_owned();
+    std::fs::write(root.join(".git/refs/heads").join(branch), "not-an-object-id
+").expect("breaks");
+    assert!(crate::recover::reflog(&git(), &root).is_err(), "the reflog says why");
+    assert!(crate::structure::lfs(&git(), &root).is_err(), "LFS says why");
+    // HEAD at a missing tag is no new branch either.
+    let other = dir.path().join("other");
+    crate::repo::init(&git(), &other).expect("init");
+    sh(&other, &["symbolic-ref", "HEAD", "refs/tags/missing"]);
+    assert!(crate::recover::reflog(&git(), &other).is_err(), "a tag HEAD says why");
 }
 
 #[test]