From 6fdd7149c1b68223c42cf5fe9994a4b78fa3d9bc Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Fri, 28 Feb 2020 16:45:35 +0000
Subject: [PATCH] drive: don't overwrite the description on sever side copy

See: https://forum.rclone.org/t/is-there-a-way-to-sync-while-keeping-file-description-on-the-destination/14609
---
 backend/drive/drive.go | 31 +++++++++++++++++++++++++------
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/backend/drive/drive.go b/backend/drive/drive.go
index feee84a69..928e089aa 100644
--- a/backend/drive/drive.go
+++ b/backend/drive/drive.go
@@ -642,17 +642,21 @@ func containsString(slice []string, s string) bool {
 	return false
 }
 
-// getRootID returns the canonical ID for the "root" ID
-func (f *Fs) getRootID() (string, error) {
-	var info *drive.File
-	var err error
+// getFile returns drive.File for the ID passed and fields passed in
+func (f *Fs) getFile(ID string, fields googleapi.Field) (info *drive.File, err error) {
 	err = f.pacer.CallNoRetry(func() (bool, error) {
-		info, err = f.svc.Files.Get("root").
-			Fields("id").
+		info, err = f.svc.Files.Get(ID).
+			Fields(fields).
 			SupportsAllDrives(true).
 			Do()
 		return f.shouldRetry(err)
 	})
+	return info, err
+}
+
+// getRootID returns the canonical ID for the "root" ID
+func (f *Fs) getRootID() (string, error) {
+	info, err := f.getFile("root", "id")
 	if err != nil {
 		return "", errors.Wrap(err, "couldn't find root directory ID")
 	}
@@ -2042,11 +2046,13 @@ func (f *Fs) Precision() time.Duration {
 func (f *Fs) Copy(ctx context.Context, src fs.Object, remote string) (fs.Object, error) {
 	var srcObj *baseObject
 	ext := ""
+	readDescription := false
 	switch src := src.(type) {
 	case *Object:
 		srcObj = &src.baseObject
 	case *documentObject:
 		srcObj, ext = &src.baseObject, src.ext()
+		readDescription = true
 	case *linkObject:
 		srcObj, ext = &src.baseObject, src.ext()
 	default:
@@ -2070,6 +2076,19 @@ func (f *Fs) Copy(ctx context.Context, src fs.Object, remote string) (fs.Object,
 		return nil, err
 	}
 
+	if readDescription {
+		// preserve the description on copy for docs
+		info, err := f.getFile(srcObj.id, "description")
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to read description for Google Doc")
+		}
+		createInfo.Description = info.Description
+	} else {
+		// don't overwrite the description on copy for files
+		// this should work for docs but it doesn't - it is probably a bug in Google Drive
+		createInfo.Description = ""
+	}
+
 	var info *drive.File
 	err = f.pacer.Call(func() (bool, error) {
 		info, err = f.svc.Files.Copy(srcObj.id, createInfo).