Add bindings for git_remote_default_branch (#572)

libgit2-sys/lib.rs

@@ -2049,6 +2049,7 @@ extern "C" {
         remote: *mut git_remote,
         callbacks: *const git_remote_callbacks,
     ) -> c_int;
+    pub fn git_remote_default_branch(out: *mut git_buf, remote: *mut git_remote) -> c_int;
 
     // refspec
     pub fn git_refspec_direction(spec: *const git_refspec) -> git_direction;

src/remote.rs

@@ -9,7 +9,7 @@ use std::str;
 
 use crate::string_array::StringArray;
 use crate::util::Binding;
-use crate::{raw, Direction, Error, FetchPrune, Oid, ProxyOptions, Refspec};
+use crate::{raw, Buf, Direction, Error, FetchPrune, Oid, ProxyOptions, Refspec};
 use crate::{AutotagOption, Progress, RemoteCallbacks, Repository};
 
 /// A structure representing a [remote][1] of a git repository.
@@ -112,6 +112,20 @@ impl<'repo> Remote<'repo> {
         unsafe { crate::opt_bytes(self, raw::git_remote_pushurl(&*self.raw)) }
     }
 
+    /// Get the remote's default branch.
+    ///
+    /// The remote (or more exactly its transport) must have connected to the
+    /// remote repository. This default branch is available as soon as the
+    /// connection to the remote is initiated and it remains available after
+    /// disconnecting.
+    pub fn default_branch(&self) -> Result<Buf, Error> {
+        unsafe {
+            let buf = Buf::new();
+            try_call!(raw::git_remote_default_branch(buf.raw(), self.raw));
+            Ok(buf)
+        }
+    }
+
     /// Open a connection to a remote.
     pub fn connect(&mut self, dir: Direction) -> Result<(), Error> {
         // TODO: can callbacks be exposed safely?
@@ -576,6 +590,14 @@ impl<'repo, 'connection, 'cb> RemoteConnection<'repo, 'connection, 'cb> {
     pub fn list(&self) -> Result<&[RemoteHead<'_>], Error> {
         self.remote.list()
     }
+
+    /// Get the remote's default branch.
+    ///
+    /// This default branch is available as soon as the connection to the remote
+    /// is initiated and it remains available after disconnecting.
+    pub fn default_branch(&self) -> Result<Buf, Error> {
+        self.remote.default_branch()
+    }
 }
 
 impl<'repo, 'connection, 'cb> Drop for RemoteConnection<'repo, 'connection, 'cb> {