Allow overriding Git configuration when cloning.

Author: bittrance

gix/src/clone/access.rs

@@ -34,6 +34,13 @@ impl PrepareFetch {
         self.shallow = shallow;
         self
     }
+
+    /// Apply the given configuration `values` early to allow affecting the repository instantiation phase.
+    /// The configuration is marked with [source API][gix_config::Source::Api].
+    pub fn config_overrides(mut self, values: impl IntoIterator<Item = impl Into<BString>>) -> Self {
+        self.api_config_overrides = values.into_iter().map(Into::into).collect();
+        self
+    }
 }
 
 /// Consumption

gix/src/clone/fetch/mod.rs

@@ -18,6 +18,10 @@ pub enum Error {
     RemoteConnection(#[source] Box<dyn std::error::Error + Send + Sync>),
     #[error(transparent)]
     RemoteName(#[from] crate::config::remote::symbolic_name::Error),
+    #[error(transparent)]
+    ParseConfig(#[from] crate::config::overrides::Error),
+    #[error(transparent)]
+    ApplyConfig(#[from] crate::config::Error),
     #[error("Failed to load repo-local git configuration before writing")]
     LoadConfig(#[from] gix_config::file::init::from_paths::Error),
     #[error("Failed to store configured remote in memory")]
@@ -75,6 +79,10 @@ impl PrepareFetch {
             .as_mut()
             .expect("user error: multiple calls are allowed only until it succeeds");
 
+        let mut snapshot = repo.config_snapshot_mut();
+        snapshot.append_config(self.api_config_overrides.as_slice(), gix_config::Source::Api)?;
+        snapshot.commit()?;
+
         let remote_name = match self.remote_name.as_ref() {
             Some(name) => name.to_owned(),
             None => repo

gix/src/clone/mod.rs

@@ -20,6 +20,8 @@ pub struct PrepareFetch {
     repo: Option<crate::Repository>,
     /// The name of the remote, which defaults to `origin` if not overridden.
     remote_name: Option<BString>,
+    /// Additional config `values` that are applied in-memory before starting the fetch process.
+    api_config_overrides: Vec<BString>,
     /// A function to configure a remote prior to fetching a pack.
     configure_remote: Option<ConfigureRemoteFn>,
     /// A function to configure a connection before using it.
@@ -126,6 +128,7 @@ impl PrepareFetch {
             #[cfg(any(feature = "async-network-client", feature = "blocking-network-client"))]
             fetch_options: Default::default(),
             repo: Some(repo),
+            api_config_overrides: Vec::new(),
             remote_name: None,
             configure_remote: None,
             #[cfg(any(feature = "async-network-client", feature = "blocking-network-client"))]