Merge pull request #1250 from DanielEScherzer/remote-empty-list

Fix `Remote::list()` with an empty list

Author: weihanglo

src/remote.rs

@@ -384,6 +384,18 @@ impl<'repo> Remote<'repo> {
                 mem::size_of::<RemoteHead<'_>>(),
                 mem::size_of::<*const raw::git_remote_head>()
             );
+            if base.is_null() {
+                // We cannot use slice::from_raw_parts() since that requires
+                // that the pointer be non-null, but that is fine since the size
+                // should be zero
+                if size != 0 {
+                    return Err(Error::from_str(&format!(
+                        "git_remote_ls() set a null pointer for a list of size {}",
+                        size
+                    )));
+                }
+                return Ok(&[]);
+            }
             let slice = slice::from_raw_parts(base as *const _, size as usize);
             Ok(mem::transmute::<
                 &[*const raw::git_remote_head],
@@ -921,6 +933,27 @@ mod tests {
         drop(origin.clone());
     }
 
+    #[test]
+    fn empty_remote_list() {
+        // Regression tests for issue #1217
+        let td = TempDir::new().unwrap();
+        let repo = Repository::init(td.path()).unwrap();
+
+        let remote_dir = TempDir::new().unwrap();
+        let _remote_repo = Repository::init_bare(remote_dir.path()).unwrap();
+        let remote_url = if cfg!(unix) {
+            format!("file://{}", remote_dir.path().display())
+        } else {
+            format!(
+                "file:///{}",
+                remote_dir.path().display().to_string().replace("\\", "/")
+            )
+        };
+        let mut remote = repo.remote("origin", &remote_url).unwrap();
+        remote.connect(Direction::Fetch).unwrap();
+        assert_eq!(0, remote.list().unwrap().len());
+    }
+
     #[test]
     fn is_valid_name() {
         assert!(Remote::is_valid_name("foobar"));