.

wcfs/wcfs.go

@@ -1406,6 +1406,7 @@ func (wlink *WatchLink) setupWatch(ctx context.Context, foid zodb.Oid, at zodb.T
 	// XXX locking
 
 	// pin all tracked file blocks that were changed in (at, head] range
+	// XXX blk in w.pinned; blk not in δ -> unpin to head
 	f := w.file
 	for _, δfile := range bfdir.δFtail.SliceByFileRev(f, at, headAt) {
 		for blk := range δfile.Blocks {
@@ -1422,6 +1423,9 @@ func (wlink *WatchLink) setupWatch(ctx context.Context, foid zodb.Oid, at zodb.T
 		}
 	}
 
+	// XXX locking
+	w.at = at
+
 	wg, ctx := errgroup.WithContext(ctx)
 	for blk, rev := range toPin {
 		blk := blk