Provide world Git identity, reflog fallback, object inspection, and which (T73)

userland/git/src/branches.rs

@@ -57,30 +57,54 @@ pub(crate) struct BranchDeleted {
     pub reference: String,
 }
 
-/// Reflogs require an identity, but switching branches must not require configuring one.
-/// With no repository identity, leave reflogs untouched and report that explicitly; never invent an author.
+/// Reflog-only writes use a fallback identity when the repository has none.
+pub(crate) fn reflog_signature(repo: &gix::Repository) -> Result<gix::actor::Signature> {
+    if let Some(signature) = repo
+        .committer()
+        .transpose()
+        .map_err(|e| error("reflog identity", e))?
+    {
+        return signature
+            .to_owned()
+            .map_err(|e| error("reflog identity", e));
+    }
+    let config = repo.config_snapshot();
+    let name = std::env::var("GIT_COMMITTER_NAME")
+        .ok()
+        .or_else(|| config.string("user.name").map(|s| s.to_string()))
+        .or_else(|| std::env::var("USER").ok())
+        .unwrap_or_else(|| "Sausage".into());
+    let email = std::env::var("GIT_COMMITTER_EMAIL")
+        .ok()
+        .or_else(|| config.string("user.email").map(|s| s.to_string()))
+        .unwrap_or_else(|| {
+            format!(
+                "{}@{}",
+                std::env::var("USER").unwrap_or_else(|_| "sausage".into()),
+                std::env::var("HOSTNAME").unwrap_or_else(|_| "localhost".into())
+            )
+        });
+    let seconds = std::time::SystemTime::now()
+        .duration_since(std::time::UNIX_EPOCH)
+        .unwrap()
+        .as_secs() as i64;
+    Ok(gix::actor::Signature {
+        name: name.into(),
+        email: email.into(),
+        time: gix::date::Time::new(seconds, 0),
+    })
+}
+
+/// Publish references and their reflog entries without requiring a commit identity.
 pub(crate) fn edit_refs(
     repo: &gix::Repository,
     edits: Vec<gix::refs::transaction::RefEdit>,
 ) -> Result<Vec<String>> {
-    let committer = repo
-        .committer()
-        .transpose()
-        .map_err(|e| error("reflog identity", e))?;
-    if let Some(committer) = committer {
-        repo.edit_references_as(edits, Some(committer))
-            .map_err(|e| error("checkout refs", e))?;
-        Ok(Vec::new())
-    } else {
-        let mut local = repo.clone();
-        local.refs.write_reflog = gix::refs::store::WriteReflog::Disable;
-        local
-            .edit_references_as(edits, None)
-            .map_err(|e| error("checkout refs", e))?;
-        Ok(vec![
-            "reflog not written: no repository committer identity configured".into(),
-        ])
-    }
+    let signature = reflog_signature(repo)?;
+    let mut time = Default::default();
+    repo.edit_references_as(edits, Some(signature.to_ref(&mut time)))
+        .map_err(|e| error("checkout refs", e))?;
+    Ok(Vec::new())
 }
 
 pub(crate) fn branch_name(name: &str) -> Result<String> {