copy,move: restore --no-traverse flag

The --no-traverse flag was not implemented when the new sync routines
(using the march package) was implemented.

This re-implements --no-traverse in march by trying to find a match
for each object with NewObject rather than from a directory listing.

fs/sync/sync.go

@@ -29,6 +29,7 @@ type syncCopyMove struct {
 	// internal state
 	ctx            context.Context        // internal context for controlling go-routines
 	cancel         func()                 // cancel the context
+	noTraverse     bool                   // if set don't traverse the dst
 	deletersWg     sync.WaitGroup         // for delete before go routine
 	deleteFilesCh  chan fs.Object         // channel to receive deletes if delete before
 	trackRenames   bool                   // set if we should do server side renames
@@ -75,6 +76,7 @@ func newSyncCopyMove(fdst, fsrc fs.Fs, deleteMode fs.DeleteMode, DoMove bool, de
 		dstFilesResult:     make(chan error, 1),
 		dstEmptyDirs:       make(map[string]fs.DirEntry),
 		srcEmptyDirs:       make(map[string]fs.DirEntry),
+		noTraverse:         fs.Config.NoTraverse,
 		toBeChecked:        newPipe(accounting.Stats.SetCheckQueue, fs.Config.MaxBacklog),
 		toBeUploaded:       newPipe(accounting.Stats.SetTransferQueue, fs.Config.MaxBacklog),
 		deleteFilesCh:      make(chan fs.Object, fs.Config.Checkers),
@@ -84,6 +86,10 @@ func newSyncCopyMove(fdst, fsrc fs.Fs, deleteMode fs.DeleteMode, DoMove bool, de
 		trackRenamesCh:     make(chan fs.Object, fs.Config.Checkers),
 	}
 	s.ctx, s.cancel = context.WithCancel(context.Background())
+	if s.noTraverse && s.deleteMode != fs.DeleteModeOff {
+		fs.Errorf(nil, "Ignoring --no-traverse with sync")
+		s.noTraverse = false
+	}
 	if s.trackRenames {
 		// Don't track renames for remotes without server-side move support.
 		if !operations.CanServerSideMove(fdst) {
@@ -104,6 +110,10 @@ func newSyncCopyMove(fdst, fsrc fs.Fs, deleteMode fs.DeleteMode, DoMove bool, de
 		if s.deleteMode != fs.DeleteModeOff {
 			s.deleteMode = fs.DeleteModeAfter
 		}
+		if s.noTraverse {
+			fs.Errorf(nil, "Ignoring --no-traverse with --track-renames")
+			s.noTraverse = false
+		}
 	}
 	// Make Fs for --backup-dir if required
 	if fs.Config.BackupDir != "" {
@@ -651,6 +661,7 @@ func (s *syncCopyMove) run() error {
 		Fdst:          s.fdst,
 		Fsrc:          s.fsrc,
 		Dir:           s.dir,
+		NoTraverse:    s.noTraverse,
 		Callback:      s,
 		DstIncludeAll: filter.Active.Opt.DeleteExcluded,
 	}