git: return better error message when packfile cannot be downloaded

Previously the error message when the connection was closed while
fetching was "object not found" and was misleading. Now when the
packfile size is 0 the error "unable to fetch packfile" is returned.

Signed-off-by: Javi Fontan <jfontan@gmail.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/plumbing/format/packfile/common.go b/plumbing/format/packfile/common.go
index 2b4aceb..0d9ed54 100644
--- a/plumbing/format/packfile/common.go
+++ b/plumbing/format/packfile/common.go
@@ -51,7 +51,13 @@ func WritePackfileToObjectStorage(
 	}
 
 	defer ioutil.CheckClose(w, &err)
-	_, err = io.Copy(w, packfile)
+
+	var n int64
+	n, err = io.Copy(w, packfile)
+	if err == nil && n == 0 {
+		return ErrEmptyPackfile
+	}
+
 	return err
 }