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-actor/src/signature/decode.rs

@@ -1,7 +1,9 @@
 pub(crate) mod function {
+    use crate::{IdentityRef, SignatureRef};
     use bstr::ByteSlice;
     use gix_date::{time::Sign, OffsetInSeconds, SecondsSinceUnixEpoch, Time};
     use gix_utils::btoi::to_signed;
+    use winnow::error::{ErrMode, ErrorKind};
     use winnow::{
         combinator::{alt, separated_pair, terminated},
         error::{AddContext, ParserError, StrContext},
@@ -10,8 +12,6 @@ pub(crate) mod function {
         token::{take, take_until, take_while},
     };
 
-    use crate::{IdentityRef, SignatureRef};
-
     const SPACE: &[u8] = b" ";
 
     /// Parse a signature from the bytes input `i` using `nom`.
@@ -64,6 +64,9 @@ pub(crate) mod function {
     pub fn identity<'a, E: ParserError<&'a [u8]> + AddContext<&'a [u8], StrContext>>(
         i: &mut &'a [u8],
     ) -> PResult<IdentityRef<'a>, E> {
+        let eol = i
+            .find_byte(b'\n')
+            .ok_or(ErrMode::Cut(E::from_error_kind(i, ErrorKind::Eof)))?;
         (
             terminated(take_until(0.., &b" <"[..]), take(2usize)).context(StrContext::Expected("<name>".into())),
             terminated(take_until(0.., &b">"[..]), take(1usize)).context(StrContext::Expected("<email>".into())),

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