From 415eeca6cf5e05b5137a6ef092787a23ccd308a7 Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Sun, 10 Mar 2019 15:47:34 +0000
Subject: [PATCH] drive: fix range requests on 0 length files

Before this change a range request on a 0 length file would fail

    $ rclone cat --head 128 drive:test/emptyfile
    ERROR : open file failed: googleapi: Error 416: Request range not satisfiable, requestedRangeNotSatisfiable

To fix this we remove Range: headers on requests for zero length files.
---
 backend/drive/drive.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/backend/drive/drive.go b/backend/drive/drive.go
index dc6ea4c8c..db02bbc73 100644
--- a/backend/drive/drive.go
+++ b/backend/drive/drive.go
@@ -2436,6 +2436,10 @@ func (o *baseObject) httpResponse(url, method string, options []fs.OpenOption) (
 		return req, nil, err
 	}
 	fs.OpenOptionAddHTTPHeaders(req.Header, options)
+	if o.bytes == 0 {
+		// Don't supply range requests for 0 length objects as they always fail
+		delete(req.Header, "Range")
+	}
 	err = o.fs.pacer.Call(func() (bool, error) {
 		res, err = o.fs.client.Do(req)
 		if err == nil {