reproduce failure when parsing malformed commit (#1438)

Note that Git can parse it.

It's notable that it parses the name as `Gregor Hartmann`
and the email as `gh <Gregor Hartmann<[email protected]`,
while the author/commiter lines are
`Gregor Hartmann<gh <Gregor Hartmann<[email protected]>>`

Author: Byron

gix-object/tests/commit/from_bytes.rs

@@ -35,6 +35,32 @@ fn invalid_timestsamp() {
     );
 }
 
+#[test]
+fn invalid_email_of_committer() {
+    let actor = gix_actor::SignatureRef {
+        name: b"Gregor Hartmann<gh".as_bstr(),
+        email: b"Gregor Hartmann<[email protected]>".as_bstr(),
+        time: Time {
+            seconds: 1270814970,
+            offset: 2 * 60 * 60,
+            sign: Sign::Plus,
+        },
+    };
+    assert_eq!(
+        CommitRef::from_bytes(&fixture_name("commit", "invalid-actor.txt"))
+            .expect("ignore strangely formed actor format"),
+        CommitRef {
+            tree: b"aee896327aa08c20f9ce80c9060aefe47edc65be".as_bstr(),
+            parents: [b"d93091832789fc586916720da62a341a731fbd66".as_bstr()].into(),
+            author: actor,
+            committer: actor,
+            encoding: None,
+            message: b"add methods for tablecontrol".as_bstr(),
+            extra_headers: vec![]
+        }
+    );
+}
+
 #[test]
 fn unsigned() -> crate::Result {
     assert_eq!(

gix-object/tests/fixtures/commit/invalid-actor.txt

@@ -0,0 +1,6 @@
+tree 220738fd4199e95a2b244465168366a73ebdf271
+parent 209fbe2d632761b30b7b17422914e11b93692833
+author Gregor Hartmann<gh <Gregor Hartmann<[email protected]>> 1282910542 +0200
+committer Gregor Hartmann<gh <Gregor Hartmann<[email protected]>> 1282910542 +0200
+
+build breakers