post-update signature stuff

Adapt to changes in `gix-actor::Signature` and `gix-actor::SignatureRef`. The latter now contains an unparsed
string time field, while the former still contains a parsed time.
So, the conversions between `gix-actor::SignatureRef` and either `gix-actor::Signature` or jj's `Signature` types can now fail.

Cc: GitoxideLabs/gitoxide#1935, GitoxideLabs/gitoxide#2038

Author: ilyagr

lib/src/git_backend.rs

@@ -652,14 +652,13 @@ fn signature_from_git(signature: gix::actor::SignatureRef) -> Signature {
     } else {
         "".to_string()
     };
-    let timestamp = MillisSinceEpoch(signature.time.seconds * 1000);
-    let tz_offset = signature.time.offset.div_euclid(60); // in minutes
+    let time = signature.time().unwrap_or_default();
     Signature {
         name,
         email,
         timestamp: Timestamp {
-            timestamp,
-            tz_offset,
+            timestamp: MillisSinceEpoch(time.seconds * 1000),
+            tz_offset: time.offset.div_euclid(60), // in minutes
         },
     }
 }
@@ -1599,6 +1598,7 @@ fn bytes_vec_from_json(value: &serde_json::Value) -> Vec<u8> {
 #[cfg(test)]
 mod tests {
     use assert_matches::assert_matches;
+    use gix::date::parse::TimeBuf;
     use hex::ToHex as _;
     use pollster::FutureExt as _;
 
@@ -1671,8 +1671,8 @@ mod tests {
         };
         let git_commit_id = git_repo
             .commit_as(
-                &git_committer,
-                &git_author,
+                git_committer.to_ref(&mut TimeBuf::default()),
+                git_author.to_ref(&mut TimeBuf::default()),
                 "refs/heads/dummy",
                 "git commit message",
                 root_tree_id,
@@ -1698,8 +1698,8 @@ mod tests {
         // Add an empty commit on top
         let git_commit_id2 = git_repo
             .commit_as(
-                &git_committer,
-                &git_author,
+                git_committer.to_ref(&mut TimeBuf::default()),
+                git_author.to_ref(&mut TimeBuf::default()),
                 "refs/heads/dummy2",
                 "git commit message 2",
                 root_tree_id,
@@ -1823,8 +1823,8 @@ mod tests {
             gix::ObjectId::from_hex(b"4b825dc642cb6eb9a060e54bf8d69288fbee4904").unwrap();
         let git_commit_id = git_repo
             .commit_as(
-                &signature,
-                &signature,
+                signature.to_ref(&mut TimeBuf::default()),
+                signature.to_ref(&mut TimeBuf::default()),
                 "refs/heads/main",
                 "git commit message",
                 empty_tree_id,
@@ -1954,20 +1954,20 @@ mod tests {
 
     #[test]
     fn read_empty_string_placeholder() {
-        let git_signature1 = gix::actor::SignatureRef {
+        let git_signature1 = gix::actor::Signature {
             name: EMPTY_STRING_PLACEHOLDER.into(),
             email: "git.author@example.com".into(),
             time: gix::date::Time::new(1000, 60 * 60),
         };
-        let signature1 = signature_from_git(git_signature1);
+        let signature1 = signature_from_git(git_signature1.to_ref(&mut TimeBuf::default()));
         assert!(signature1.name.is_empty());
         assert_eq!(signature1.email, "git.author@example.com");
-        let git_signature2 = gix::actor::SignatureRef {
+        let git_signature2 = gix::actor::Signature {
             name: "git committer".into(),
             email: EMPTY_STRING_PLACEHOLDER.into(),
             time: gix::date::Time::new(2000, -480 * 60),
         };
-        let signature2 = signature_from_git(git_signature2);
+        let signature2 = signature_from_git(git_signature2.to_ref(&mut TimeBuf::default()));
         assert_eq!(signature2.name, "git committer");
         assert!(signature2.email.is_empty());
     }
@@ -2242,8 +2242,8 @@ mod tests {
             gix::ObjectId::from_hex(b"4b825dc642cb6eb9a060e54bf8d69288fbee4904").unwrap();
         let git_commit_id = git_repo
             .commit_as(
-                &signature,
-                &signature,
+                signature.to_ref(&mut TimeBuf::default()),
+                signature.to_ref(&mut TimeBuf::default()),
                 "refs/heads/main",
                 "git commit message",
                 empty_tree_id,

lib/testutils/src/git.rs

@@ -15,6 +15,8 @@
 use std::path::Path;
 use std::path::PathBuf;
 
+use gix::date::parse::TimeBuf;
+
 pub const GIT_USER: &str = "Someone";
 pub const GIT_EMAIL: &str = "someone@example.org";
 
@@ -150,8 +152,8 @@ pub fn write_commit(
 ) -> gix::ObjectId {
     let signature = signature();
     repo.commit_as(
-        &signature,
-        &signature,
+        signature.to_ref(&mut TimeBuf::default()),
+        signature.to_ref(&mut TimeBuf::default()),
         reference,
         message,
         tree_id,