feat: add Repository::committer_or_set_generic_fallback().

That way one can always obtain a committer, even though it might
not represent the entity actually committing.

Author: Byron

gix/src/clone/fetch/mod.rs

@@ -81,23 +81,11 @@ impl PrepareFetch {
             .as_mut()
             .expect("user error: multiple calls are allowed only until it succeeds");
 
-        if repo.committer().is_none() {
-            let mut config = gix_config::File::new(gix_config::file::Metadata::api());
-            config
-                .set_raw_value(&gitoxide::Committer::NAME_FALLBACK, "no name configured during fetch")
-                .expect("works - statically known");
-            config
-                .set_raw_value(&gitoxide::Committer::EMAIL_FALLBACK, "[email protected]")
-                .expect("works - statically known");
-            let mut repo_config = repo.config_snapshot_mut();
-            repo_config.append(config);
-            repo_config.commit().expect("configuration is still valid");
-        }
+        repo.committer_or_set_generic_fallback()?;
 
         if !self.config_overrides.is_empty() {
             let mut snapshot = repo.config_snapshot_mut();
             snapshot.append_config(&self.config_overrides, gix_config::Source::Api)?;
-            snapshot.commit()?;
         }
 
         let remote_name = match self.remote_name.as_ref() {

gix/src/clone/mod.rs

@@ -1,5 +1,5 @@
 #![allow(clippy::result_large_err)]
-use crate::{bstr::BString, config::tree::gitoxide, remote};
+use crate::{bstr::BString, remote};
 
 type ConfigureRemoteFn =
     Box<dyn FnMut(crate::Remote<'_>) -> Result<crate::Remote<'_>, Box<dyn std::error::Error + Send + Sync>>>;
@@ -46,6 +46,8 @@ pub enum Error {
     #[error(transparent)]
     Init(#[from] crate::init::Error),
     #[error(transparent)]
+    CommitterOrFallback(#[from] crate::config::time::Error),
+    #[error(transparent)]
     UrlParse(#[from] gix_url::parse::Error),
     #[error("Failed to turn a the relative file url \"{}\" into an absolute one", url.to_bstring())]
     CanonicalizeUrl {
@@ -102,18 +104,7 @@ impl PrepareFetch {
                 url: url.clone(),
                 source: err,
             })?;
-        if repo.committer().is_none() {
-            let mut config = gix_config::File::new(gix_config::file::Metadata::api());
-            config
-                .set_raw_value(&gitoxide::Committer::NAME_FALLBACK, "no name configured during clone")
-                .expect("works - statically known");
-            config
-                .set_raw_value(&gitoxide::Committer::EMAIL_FALLBACK, "[email protected]")
-                .expect("works - statically known");
-            let mut repo_config = repo.config_snapshot_mut();
-            repo_config.append(config);
-            repo_config.commit().expect("configuration is still valid");
-        }
+        repo.committer_or_set_generic_fallback()?;
         Ok(PrepareFetch {
             url,
             #[cfg(any(feature = "async-network-client", feature = "blocking-network-client"))]

gix/src/repository/identity.rs

@@ -43,6 +43,24 @@ impl crate::Repository {
         .into()
     }
 
+    /// Return the committer or its fallback just like [`committer()`](Self::committer()), but if *not* set generate a
+    /// possibly arbitrary fallback and configure it in memory on this instance. That fallback is then returned and future
+    /// calls to [`committer()`](Self::committer()) will return it as well.
+    pub fn committer_or_set_generic_fallback(&mut self) -> Result<gix_actor::SignatureRef<'_>, config::time::Error> {
+        if self.committer().is_none() {
+            let mut config = gix_config::File::new(gix_config::file::Metadata::api());
+            config
+                .set_raw_value(&gitoxide::Committer::NAME_FALLBACK, "no name configured during fetch")
+                .expect("works - statically known");
+            config
+                .set_raw_value(&gitoxide::Committer::EMAIL_FALLBACK, "[email protected]")
+                .expect("works - statically known");
+            let mut repo_config = self.config_snapshot_mut();
+            repo_config.append(config);
+        }
+        self.committer().expect("committer was just set")
+    }
+
     /// Return the author as configured by this repository, which is determined by…
     ///
     /// * …the git configuration `author.name|email`…

gix/tests/gix-init.rs

@@ -268,7 +268,7 @@ mod with_overrides {
         Ok(())
     }
 
-    fn cow_bstr(s: &str) -> Cow<BStr> {
+    fn cow_bstr(s: &str) -> Cow<'_, BStr> {
         Cow::Borrowed(s.into())
     }
 }

gix/tests/gix/object/tree/diff.rs

@@ -879,7 +879,7 @@ mod track_rewrites {
     }
 }
 
-fn tree_named(repo: &gix::Repository, rev_spec: impl AsRef<str>) -> gix::Tree {
+fn tree_named(repo: &gix::Repository, rev_spec: impl AsRef<str>) -> gix::Tree<'_> {
     repo.rev_parse_single(rev_spec.as_ref())
         .unwrap()
         .object()