operations: call Rcat in Copy when size is -1 - #2832

fs/operations/operations.go

@@ -286,6 +286,16 @@ func Copy(f fs.Fs, dst fs.Object, remote string, src fs.Object) (newDst fs.Objec
 			in0, err = src.Open(hashOption)
 			if err != nil {
 				err = errors.Wrap(err, "failed to open source object")
+			} else {
+				if src.Size() == -1 {
+					// -1 indicates unknown size. Use Rcat to handle both remotes supporting and not supporting PutStream.
+					if doUpdate {
+						actionTaken = "Copied (Rcat, replaced existing)"
+					} else {
+						actionTaken = "Copied (Rcat, new)"
+					}
+					dst, err = Rcat(f, remote, in0, src.ModTime())
+					newDst = dst
 				} else {
 					in := accounting.NewAccount(in0, src).WithBuffer() // account and buffer the transfer
 					var wrappedSrc fs.ObjectInfo = src
@@ -307,6 +317,7 @@ func Copy(f fs.Fs, dst fs.Object, remote string, src fs.Object) (newDst fs.Objec
 					}
 				}
 			}
+		}
 		tries++
 		if tries >= maxTries {
 			break